Replace issue creation interactor with Issue model
Dont use fake issue tracker from errbit_plugin gem

Fake issue tracker is a mock tracker for tests only, it should live in errbit core
Replace issue creation interactor spec with issue_spec
Issue has_one issue_tracker
Issue tracker model should not have any view/render concerns
Fix problem_controller and spec
Fix tests
Fix more tests
Issue needs the problem model
Remove some github specific configs, need to be on the plugin
Add more tests to create_issue action
Render issue body
Show tracker errors when saving issue
use master plugin
Merge pull request #774 from errbit/refacor_issue_tracker

Refacorting issue tracker