Fix requirements for enzyme 0.3
Merge branch 'develop'

Conflicts:
	requirements.txt
	setup.py
	subliminal/infos.py
Skip empty language in addic7ed
Be more permissive in subtitle validation
Switch to 0.7.3
Updated README with proper information

Section relative to the library was invalid. Missing references and
arguments.
Improve embedded subtitles language detection
Add setuptools to dev-requirements.txt
Update to babelfish 0.4.0
Update dogpile.cache to 0.5.2 and use a MutexLock in cli
Add Podnapisi to the list of providers in documentation
Improve assertions in tests
Fix podnapisi tests
Ignore IDE error in cli
Fix wrong error catched for babelfish 0.4.0
Sync README and documentation
Release 0.7.3
Merge branch 'develop'
Fix unittests for addic7ed
Update badges in README