Release 0.3 Week 2

This week I am working on Seneca Blackboard Extension.

First Contribution

I already created first pull request. In this PR I added icons of different sizes to our project and included them into manifest.json. Now icons are shown in extensions list, extensions settings, etc.

Current Tasks

I decided to reorganize and restyle Seneca Blackboard, because it looks old-fashioned and we remove old/insert new elements (issue-8).

When we change Seneca Blackboard code, bugs appear, so I decided to fix them.
Examples:
issue-51 issue-52