Use :git gem for metasploit-model so travis-ci works
Use :git gem for metasploit-model so travis-ci works

[#50752269]

Temporarily use a :git gem entry in the Gemfile to satisfy the
metasploit-model dependency in the gemspes so that travis-ci can run the
tests.

rapid7/metasploit_data_models,bcook-r7/metasploit_data_models,bcook-r7/metasploit_data_models,farias-r7/metasploit_data_models,rapid7/metasploit-cache,farias-r7/metasploit_data_models,rapid7/metasploit-cache,rapid7/metasploit-cache,rapid7/metasploit_data_models,farias-r7/metasploit_data_models,bcook-r7/metasploit_data_models,rapid7/metasploit-cache,rapid7/metasploit_data_models