Method update DeployMasterPage, DeployPageLayout

Add parameter folderPath and deployed master pages and page layouts under it.
Also, to DeployPageLayout added parameter List <webPartEntities> to have default webparts provisioned on page layout.

Reference:
https://github.com/OfficeDev/PnP/issues/66
EnsureFolder to ensure hierarchy of folders.

Added overload method EnsureFolder to ensure hierarchy of folders.
Merge remote-tracking branch 'contributor/master' into pr138
Integrated pr138 - removed adding webparts to pagelayout during deployment + additional folder tests