add rest specific dependencies to CONTRIBUTING.md
add rest specific dependencies to CONTRIBUTING.md

This is just to ensure that we have full coverage on the extra packages
needed to create the rest server.

radanalyticsio/oshinko-cli,tmckayus/oshinko-cli,crobby/oshinko-cli,tmckayus/oshinko-cli,radanalyticsio/oshinko-cli,radanalyticsio/oshinko-cli,crobby/oshinko-cli,crobby/oshinko-cli,tmckayus/oshinko-cli