Flake8, Semver, Pre-commit

* Added pre-commit: http://pre-commit.com
* Fixed flake8 errors
* Added flake8 pre-commit hooks
* Added pre-commit to Makefile
* Changed VERSION numbering
* Changed versioning to match PEP-0440

senpy/api.py

@@ -1,9 +1,8 @@
 from future.utils import iteritems
+from .models import Error
 import logging
 logger = logging.getLogger(__name__)
 
-from .models import Error
-
 API_PARAMS = {
     "algorithm": {
         "aliases": ["algorithm", "a", "algo"],