DATACOUCH-31 - Ignore IntelliJ files
DATACOUCH-32 - Upgrade Dependencies
DATACOUCH-36 - Don't allow NULL values to be stored.

It is illegal to store a NULL value as a document. An attempt to do so will
throw an IllegalArgumentException.

-=david=-
Merge pull request #9 from dharrigan/DATACOUCH-36

DATACOUCH-36 - Don't allow NULL values to be stored.