diff --git a/Dockerfile b/Dockerfile
index 9289deb..550df7d 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -3,6 +3,7 @@ From python:2.7.9-onbuild
 Maintainer J. Fernando Sánchez @balkian
 
 # RUN pip --cert cacert.pem install -r -v  requirements.txt
+ADD . /usr/src/app/
 
-RUN pip install --editable .;
+RUN pip install -e "/usr/src/app/[server]"
 ENTRYPOINT ["bitter"]
diff --git a/MANIFEST.in b/MANIFEST.in
index dfaf48a..67a93b5 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -1,3 +1,6 @@
 include requirements.txt
 include test-requirements.txt
 include README.md
+graft bitter/templates
+graft bitter/static
+graft test
diff --git a/README.md b/README.md
index 50a0903..c92201a 100644
--- a/README.md
+++ b/README.md
@@ -41,6 +41,14 @@ To add more users to the credentials file, you may run the builtin server, with
 python -m bitter server <consumer_key> <consumer_secret>
 ```
 
+If you get an error about missing dependencies, install the extra dependencies for the server. e.g.:
+
+```
+pip install bitter[web]
+```
+
+Make sure the callback url of your app is set to http://127.0.0.1:5000/callback_url/
+
 # Notice
 Please, use according to Twitter's Terms of Service
 
diff --git a/bitter/__init__.py b/bitter/__init__.py
new file mode 100644
index 0000000..3ac18db
--- /dev/null
+++ b/bitter/__init__.py
@@ -0,0 +1,7 @@
+"""
+Bitter module. A library and cli for Twitter using python-twitter.
+http://github.com/balkian/bitter
+"""
+
+__version__ = '0.4.1'
+__all__ = ['cli', 'config', 'crawlers', 'models', 'utils' ]
diff --git a/bitter/cli.py b/bitter/cli.py
index 6d7c130..ad3733d 100644
--- a/bitter/cli.py
+++ b/bitter/cli.py
@@ -12,7 +12,14 @@ from sqlalchemy import exists
 
 from bitter import utils, models, crawlers
 from bitter.models import make_session, User, ExtractorEntry, Following
-from contextlib import ExitStack
+
+import sys
+if sys.version_info <= (3, 0):
+    from contextlib2 import ExitStack
+else:
+    from contextlib import ExitStack
+    
+
 
 logger = logging.getLogger(__name__)
 
diff --git a/bitter/utils.py b/bitter/utils.py
index 805764b..a865e3e 100644
--- a/bitter/utils.py
+++ b/bitter/utils.py
@@ -46,7 +46,10 @@ def iter_credentials(credfile=None):
 def get_credentials(credfile=None, inverse=False, **kwargs):
     creds = []
     for i in iter_credentials(credfile):
-        if all(map(lambda x: i[x[0]] == x[1], kwargs.items())):
+        matches = all(map(lambda x: i[x[0]] == x[1], kwargs.items()))
+        if matches and not inverse:
+            creds.append(i)
+        elif inverse and not matches:
             creds.append(i)
     return creds
 
diff --git a/requirements-py2.txt b/requirements-py2.txt
new file mode 100644
index 0000000..03fdf8e
--- /dev/null
+++ b/requirements-py2.txt
@@ -0,0 +1 @@
+contextlib2
diff --git a/setup.py b/setup.py
index 2e9bf94..d295ac3 100644
--- a/setup.py
+++ b/setup.py
@@ -6,16 +6,25 @@ from pip.req import parse_requirements
 # pip 6 introduces the *required* session argument
 try:
     install_reqs = parse_requirements("requirements.txt", session=pip.download.PipSession())
+    py2_reqs = parse_requirements("requirements-py2.txt", session=pip.download.PipSession())
     test_reqs = parse_requirements("test-requirements.txt", session=pip.download.PipSession())
 except AttributeError:
     install_reqs = parse_requirements("requirements.txt")
+    py2_reqs = parse_requirements("requirements-py2.txt")
     test_reqs = parse_requirements("test-requirements.txt")
 
+import sys
+import itertools
+if sys.version_info <= (3, 0):
+    install_reqs = itertools.chain(install_reqs, py2_reqs)
+
 # reqs is a list of requirement
 # e.g. ['django==1.5.1', 'mezzanine==1.4.6']
 install_reqs = [str(ir.req) for ir in install_reqs]
 test_reqs = [str(ir.req) for ir in test_reqs]
 
+with open('bitter/__init__.py') as f:
+    exec(f.read())
 
 setup(
     name="bitter",
@@ -27,9 +36,13 @@ setup(
     author='J. Fernando Sanchez',
     author_email='balkian@gmail.com',
     url="http://balkian.com",
-    version="0.4",
+    version=__version__,
     install_requires=install_reqs,
     tests_require=test_reqs,
+    extras_require = {
+        'server': ['flask', 'flask-oauthlib']
+        },
+    test_suite="tests",
     include_package_data=True,
     entry_points="""
         [console_scripts]
diff --git a/test-requirements.txt b/test-requirements.txt
index e69de29..e079f8a 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -0,0 +1 @@
+pytest
diff --git a/tests/test_crawlers.py b/tests/test_crawlers.py
deleted file mode 100644
index 6029591..0000000
--- a/tests/test_crawlers.py
+++ /dev/null
@@ -1,9 +0,0 @@
-from unittest import TestCase
-
-from bitter.crawlers import TwitterWorker, TwitterQueue
-
-class TestWorker(TestCase):
-    
-
-    def test_worker(self):
-        w = TwitterWorker()
diff --git a/tests/test_models.py b/tests/test_models.py
deleted file mode 100644
index c87a1de..0000000
--- a/tests/test_models.py
+++ /dev/null
@@ -1,6 +0,0 @@
-from unittest import TestCase
-
-class TestModels(TestCase):
-
-    def test_worker(self):
-        assert True
diff --git a/tests/test_utils.py b/tests/test_utils.py
index cc95675..c4c0f85 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -1,7 +1,50 @@
 from unittest import TestCase
 
+import os
+
+from bitter import utils
+from bitter import config as c
+
 class TestUtils(TestCase):
 
-    def test_get_user(self):
-        assert True
+    def setUp(self):
+        self.credfile = '/tmp/credentials.txt'
+        c.CREDENTIALS = self.credfile
+        if os.path.exists(self.credfile):
+            os.remove(self.credfile)
+        utils.create_credentials(self.credfile)
+        
+
+    def test_create_credentials(self):
+        assert os.path.exists(self.credfile)
+        os.remove(self.credfile)
+        utils.create_credentials() # From config
+        assert os.path.exists(self.credfile)
+
+    def test_add_credentials(self):
+        utils.add_credentials(self.credfile, user="test")
+        assert utils.get_credentials(self.credfile)
+        assert utils.get_credentials(user="test")
+        assert list(utils.get_credentials(user="test"))[0]["user"] == "test"
+
+    def test_get_credentials(self):
+        utils.add_credentials(self.credfile, user="test")
+        assert utils.get_credentials(user="test")
+        assert not utils.get_credentials(user="test", inverse=True)
+
+    def test_add_two_credentials(self):
+        utils.add_credentials(self.credfile, user="test")
+        utils.add_credentials(self.credfile, user="test2")
+        assert utils.get_credentials(user="test")
+        assert utils.get_credentials(user="test2")
+
 
+    def test_delete_credentials(self):
+        utils.add_credentials(self.credfile, user="test")
+        assert utils.get_credentials(user="test")
+        utils.delete_credentials(user="test")
+        print(utils.get_credentials())
+        assert not utils.get_credentials(user="test")
+        
+        
+