References do not get added correctly when when there is a trailing forward slash in sources of global.json file

[rmangalore]

REPRO STEPS:

1. Create a Starter web under c:\school. This gets created here-> C:\school\WebApplication2\src\WebApplication2
   1. Add a new solution folder by name Test. Add a class library to it. Say CalssLibrary1. This gets created here: C:\school\WebApplication2\ClassLibrary1
   2. Edit the global.json file to include this:
      "sources": [ "src", "test","C:/school/WebApplication2/"]
   3. Add reference to Classlibrary1 from WebApplication2.
      ACTUAL: The project.sjon gets modified to add "ClassLibrary1". The references node in WebAPplication2 does not reflect the newly added reference.

This works if the trailing "/" is removed from the Global.json file. C:/school/WebApplication2"

EXPECTED: The references node to reflect the newly added reference.