Activating extension failed if pathToSettings is configured incorrectly

[ncphillips]

Describe the bug

Extension fails to activate if configured incorrectly.

To Reproduce
Steps to reproduce the behavior:

1. Open a project with a site in a sub-directory called site
   a. the forestry config will be located at site/.forestry/settings.yml
   b. the vscode "forestry.pathToSettings" will be set to ".forestry" instead of "site/.forestry"
2. Error message is shown

Expected behavior

• Extension should successfully activate
• Show Error Message

Screenshots

Desktop (please complete the following information):

• OS: MacOS
• VSCode Version: 1.25.0
• Forestry Extension Version: 0.2.0

Static Site Generator:

• Generator: Hugo