Implement GitMate automations and plugins for coala

GitMate.io is an automation tool for developers. While it works well, there are a number of plugins which saves a lot of time of our community(for example automatically close PR's from master). Many of them are general plugins, which are required by every org, but we need more plugins which support coala development workflow(Like gitmate coala linter plugin). This project adds more automations and plugins like auto-review, auto-reject PR’s, assign, mark plugins, etc.