New versioning

Use git to automatically fetch the version

senpy/VERSION

@@ -1 +0,0 @@
-0.7.2-dev1

senpy/version.py

@@ -1,4 +1,34 @@
 import os
+import subprocess
+import logging
 
-with open(os.path.join(os.path.dirname(__file__), 'VERSION')) as f:
-    __version__ = f.read().strip()
+logger = logging.getLogger(__name__)
+
+ROOT = os.path.dirname(__file__)
+DEFAULT_FILE = os.path.join(ROOT, 'VERSION')
+
+
+def git_version():
+    try:
+        res = subprocess.check_output(['git', 'describe',
+                                       '--tags', '--dirty']).decode('utf-8')
+        return res.strip()
+    except subprocess.CalledProcessError:
+        return None
+
+
+def read_version(versionfile=DEFAULT_FILE):
+    with open(versionfile) as f:
+        return f.read().strip()
+
+
+def write_version(version, versionfile=DEFAULT_FILE):
+    version = version or git_version()
+    if not version:
+        raise ValueError('You need to provide a valid version')
+    with open(versionfile, 'w') as f:
+        f.write(version)
+
+
+__version__ = git_version() or read_version()
+write_version(__version__)