Feat/flask db hookup

[twinlensreflex]

I have:

• added the connection to the db
• added repr functions on db classes (which i thought were essential but aren't)
• added helper functions to manipulate db responses
• added javascript as a language in acceptedlangs.py
• add some print statements in twitterstream.py to clarify if someone has been added to the db
• remove duplicate "Languages: " etc from the lists I was creating in the function at the route as these exist in html
• fix the way skills are added to the db (they can now be more than one word)
• add a mentee route which duplicates the mentor route exactly