Removed App.config - keep App.config a local, untracked file
Adding App.config.sample to the core project.
adding App.config to .gitignore
Added validation of app settings to TestCommon
update docs for ECM.DocumentLibraries
Merge branch 'dev' of https://github.com/OfficeDev/PnP.git
update docs ECM.AutoTagging
Merge branch 'dev' of https://github.com/OfficeDev/PnP into dev