fix test_insert_vocabs test
Closes #5 by:
- Fixing the actual error that was causing the test to fail.
 - Updating the 
Gemfileto consolidate ruby version and dependencies. Please be aware ruby version was upgraded to2.4.0. 
Closes #5 by:
Gemfile to consolidate ruby version and dependencies. Please be aware ruby version was upgraded to 2.4.0.