Add badges (#117)

README.md

@@ -1,5 +1,10 @@
 # Mattermost Jitsi Plugin (Beta)
 
+[![Build Status](https://img.shields.io/circleci/project/github/mattermost/mattermost-plugin-jitsi/master)](https://circleci.com/gh/mattermost/mattermost-plugin-jitsi)
+[![Code Coverage](https://img.shields.io/codecov/c/github/mattermost/mattermost-plugin-jitsi/master)](https://codecov.io/gh/mattermost/mattermost-plugin-jitsi)
+[![Release](https://img.shields.io/github/v/release/mattermost/mattermost-plugin-jitsi)](https://github.com/mattermost/mattermost-plugin-jitsi/releases/latest)
+[![HW](https://img.shields.io/github/issues/mattermost/mattermost-plugin-jitsi/Up%20For%20Grabs?color=dark%20green&label=Help%20WanOted)](https://github.com/mattermost/mattermost-plugin-jitsi/issues?q=is%3Aissue+is%3Aopen+sort%3Aupdated-desc+label%3A%22Up+For+Grabs%22+label%3A%22Help+Wanted%22)
+
 **Maintainer:** [Jesús Espino](https://github.com/jespino)
 **Originally developed by:** [Sean Sackowitz](https://github.com/seansackowitz).