Update Stanford CoreNLP version to 3.3.0

The current build is based on version `3.2.x` of the Stanford CoreNLP suite
which is no longer available for download from the Stanford CoreNLP site;
only v3.3.1 is available and is __incompatible__ with the `3.2.0` dependency

Closes #4
Merge branch 'master' of github.com:ushahidi/Chambua