Remove outdated tests

[cheehongw]

There are many failing unit tests in WATcher. These tests are inherited from CATcher and require updating.

Reasons for failure fall under these 2 categories:

1. unit under test has been removed when changing from WATcher to CATcher
2. unit under test has undergone changes since CATcher

It should be relatively safe to fix category 1 since we are removing tests for files that don't exist anymore.

Fixes for category 2 should be done carefully, and should try to preserve tests cases as much as possible

To refactor test:

• Login Component
• Session Model
• Issue Paginator
• Issue Sorter
• Github Label constants
• Search Filter
• Issue Model
• Label Service
• Label Filter Bar Component
• Phase Service
• User Service

To remove test:

• markdown.css (in test env stylesheet)
• Conflict Model
• Permissions service
• Unused constants

[chunweii]

Issue is related to #72

[chunweii]

@Eclipse-Dominator Are you working on this issue? If not you can unassign yourself and let others work on this

[NereusWB922]

Hi, since the outdated tests have been refactored and the pre-push hook for npm run test is also enabled, I think we can close this issue now.