Fix typo in profile API url
Bugfix: digits in texts with no other refs would mistakenly match as an empty ref
A safety check for good links after normalization
Test framework that can be run with 'py.test', and first reference tests
Testing get_titles_in_text and get_refs_in_text
first parse_ref tests
Finish of basic texts.py English test suite
Merge pull request #92 from blockspeiser/tests

Tests
Likes for source sheets
Fix order of metrics data for graphs
Add pytest as requirement
--amend
Consolidate all DB connections across files
Only show likes on public sheets
Don't call text_at_revision for user profile activity history
Basic user to user messaging
Merge branch 'master' into messages

Conflicts:
	sefaria/urls.py
Login prompt for messaging
Event tracking for sheet likes and messages