Removed source files from the project
Reacting to System.IO.FileSystem package version change
Reacting to System.IO package version change
Fixing PhysicalFileSystem to treat absolute paths correctly
* Additionally fix PhysicalFileSystemTests to use
  IApplicationEnvironment.ApplicationBasePath

Fixes #14
Changing case for project.json
Adding TryGetParentPath to IFileSystem

Fixes #12
Updated to use the new target framework in project.json
Change how we resolve the root directory
- Read the application base from IApplicationEnvironment
  when running in the KRuntime
Removed unused PlatformHelper.cs