Iss 138 Testを通す

とりあえず下記の分通すようにしました。
本当はGithubのmockをつくるべきだと思うのですが、それも時間がかかりそうなので取り急ぎこれでマージしていただければ少しテストが楽になると思います。
rspec ./spec/models/project_spec.rb:60 # Project#modify with params[:ruffnote_full_name] creates ProjectRuffnote
rspec ./spec/models/project_spec.rb:52 # Project#modify with params[:github_full_name] creates ProjectGithub
rspec ./spec/models/project_spec.rb:109 # Project#add_github full_name has one full-width space should be trim space
rspec ./spec/models/project_spec.rb:86 # Project#add_github with valid params should be return true
rspec ./spec/models/project_spec.rb:117 # Project#add_github full_name has two full-width space should be trim space
rspec ./spec/models/project_spec.rb:93 # Project#add_github full_name has one half-width space should be trim space
rspec ./spec/models/project_spec.rb:101 # Project#add_github full_name has two half-width space should be trim space
rspec ./spec/models/project_spec.rb:77 # Project#github should be return ProjectGithub
rspec ./spec/models/project_spec.rb:38 # Project#providers should be return array with ProjectGithub
rspec ./spec/models/project_spec.rb:69 # Project#github_full_name returns github full name