Refresh after a file change is unnecessary

[ramya-rao-a]

Issue Type: Bug

• Expand one of the first level nodes like "All"
• Make a change to any file in the workspace
• Observe that the expanded first level node gets refreshed

Changes in files do not need a PR refersh

Extension version: 0.1.2
VS Code version: Code - Insiders 1.28.0-insider (96854113091424c07b28ba84b82b75a88b8455cb, 2018-09-10T05:18:57.119Z)
OS version: Windows_NT x64 10.0.17134