[BUG] value coming from GERRIT_PROJECT must be URL encoded for gerrit API calls :)

[sheputis]

The 'project' name is not URL encoded, so whenever it has characters that need to be URL encoded, gergich fails.

For example if the GERRIT_PROJECT env variable is something like 'some/project', then it is put into the URL string(for the gerrit API calls) as is, but it should be encoded to be 'some%2Fproject'.

since i dont have the permissions to push a pull request, im writing a proposal here:

1. change lib/gergich.rb:55 to "#{ERB::Util.url_encode info[:project]}~#{ERB::Util.url_encode info[:branch]}~#{info[:change_id]}"
2. Adapt test in spec/gergich_spec.rb:64

[sheputis]

added the change here #8