Version specific not.finished files, etc

`not.finished` files are now version specific, old `not.finished` files will simply not be loaded preventing any issues with feature changes that require new arguments.

Minimum Python version is now enforced properly, it should now be impossible to install (via `pip`) with an unsupported Python version.

Bandcamp-dl version is now located in setup.py only with it being added to a generated `__init__.py` during packaging or install.

bandcamp_dl/__main__.py

@@ -59,15 +59,16 @@
 
 from bandcamp_dl.bandcamp import Bandcamp
 from bandcamp_dl.bandcampdownloader import BandcampDownloader
+from bandcamp_dl.__init__ import __version__
 
 
 def main():
-    arguments = docopt(__doc__, version='bandcamp-dl 0.0.8-1')
+    arguments = docopt(__doc__, version='bandcamp-dl {}'.format(__version__))
 
     bandcamp = Bandcamp()
 
     basedir = arguments['--base-dir'] or os.getcwd()
-    session_file = basedir + "/not.finished"
+    session_file = "{}/{}.not.finished".format(basedir, __version__)
 
     if os.path.isfile(session_file):
         with open(session_file, "r") as f:

bandcamp_dl/bandcamp.py

@@ -6,11 +6,12 @@
 from bs4 import FeatureNotFound
 
 from bandcamp_dl.bandcampjson import BandcampJSON
+from bandcamp_dl.__init__ import __version__
 
 
 class Bandcamp:
     def __init__(self):
-        self.headers = {'User-Agent': 'bandcamp-dl/0.0.8-02 (https://github.com/iheanyi/bandcamp-dl)'}
+        self.headers = {'User-Agent': 'bandcamp-dl/{} (https://github.com/iheanyi/bandcamp-dl)'.format(__version__)}
 
     def parse(self, url: str, art: bool=True) -> dict or None:
         """Requests the page, cherry picks album info

bandcamp_dl/bandcampdownloader.py

@@ -13,6 +13,8 @@
     import mock
     from bandcamp_dl.utils import requests_patch
 
+from bandcamp_dl.__init__ import __version__
+
 
 class BandcampDownloader:
     def __init__(self, urls=None, template=None, directory=None, overwrite=False, lyrics=None, grouping=None,
@@ -24,7 +26,7 @@ def __init__(self, urls=None, template=None, directory=None, overwrite=False, ly
         :param directory: download location
         :param overwrite: if True overwrite existing files
         """
-        self.headers = {'User-Agent': 'bandcamp-dl/0.0.8-02 (https://github.com/iheanyi/bandcamp-dl)'}
+        self.headers = {'User-Agent': 'bandcamp-dl/{} (https://github.com/iheanyi/bandcamp-dl)'.format(__version__)}
         self.session = requests.Session()
 
         if type(urls) is str:

setup.py

@@ -3,14 +3,21 @@
 from os import path
 import sys
 
-if sys.version_info[0] == 2:
-    sys.exit('Python 2 is unsupported.')
+appversion = "0.0.8-03"
+pyversion = int("{}{}".format(sys.version_info[0], sys.version_info[1]))
+
+if not pyversion >= 34:
+    print('Python 3.4+ is required')
+    sys.exit(1)
 
 here = path.abspath(path.dirname(__file__))
 
+with open(here + '/bandcamp_dl/__init__.py', 'w') as initpy:
+    initpy.write('__version__ = "{}"'.format(appversion))
+
 setup(
     name='bandcamp-downloader',
-    version='0.0.8-02',
+    version=appversion,
     description='bandcamp-dl downloads albums and tracks from Bandcamp for you',
     long_description=open('README.rst').read(),
     url='https://github.com/iheanyi/bandcamp-dl',