Hooked up Engagement Index with API

https://jira.ets.berkeley.edu/jira/browse/CYB-82

PR crucial for today's meeting

Hooked up @richcreationsrc Engagement Index with DataCulture's API
DataCultures can query it's DB and bring relevant information to Engagement Index
A hash in the #where clauses here is more readable than the inline SQL:  {canvas_user_id: id}.  Also, you should be able to do this with one query and not make n-many queries (where n=number of students in set).   I will see if I can find an AR way to do it (rather than dropping into SQL; which most certainly can do it).