Fixes #1053: exclude NCrunch ItemGroup when NCrunch not present

[AGBrown]

This adds a condition to the ItemGroup that is required for NCrunch so that it is excluded when NCrunch is not installed. This is similar to the conditions here and here which also affect a section depending on the presence of NCrunch

[AGBrown]

appveyor error is seemingly unrelated:

Cake.exe : An error occured when executing task 'Create-Release-Notes'.
At line:1 char:1
+ & "C:\projects\gitversion\tools\Cake\Cake.exe" "build.cake" -target=" ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (An error occure...Release-Notes'.:String) [], RemoteException
    + FullyQualifiedErrorId : NativeCommandError

Error: 
Could not find file 'C:\projects\gitversion\build\releasenotes.md'.
Command executed with exception: 

travis timed out:

No output has been received in the last 10m0s, this potentially indicates a stalled build or something wrong with the build itself.
Check the details on how to adjust your build configuration on: https://docs.travis-ci.com/user/common-build-problems/#Build-times-out-because-no-output-was-received
The build has been terminated

[pascalberger]

@gep13 Any idea why AppVeyor tried to create release notes? I think we removed this for PR builds

[pascalberger]

@AGBrown You have created the PR to merge into GitTools:support/3.6.0 which tries to build release notes also for PRs (and fails with that). Can you please change the PR to merge into master instead?

[AGBrown]

@pascalberger yes, I can do that. Does that mean that (if accepted) it will still get applied to the support/v3.6.0 branch as well?

Sorry for the confusion - I was looking at the support branch and it looked like previous PRs (e.g. 9846b20) had been merged to the support branch first (e.g. 5ad3173), and then back-merged into master (e.g. 08f882e).

I'll change the PR tonight/tomorrow for you.

[AGBrown]

Closing to redo this based on master instead

[AGBrown]

Re-opened as per @JakeGinnivan request

Would you be able to submit a pr against the 3.6 branch?

[JakeGinnivan]

Thanks @AGBrown