Travis CI build failing unable to find NuGet.Core.dll

[ctaggart]

https://travis-ci.org/ctaggart/SourceLink/builds/18991246#L146

/Users/travis/build/ctaggart/SourceLink/build.fsx(1,1): error FS0078: Unable to find the file 'NuGet.Core.dll' in any of

[ctaggart]

I've got my Mac setup now and I'm able to reproduce it.

fsharpi -d:MONO build.fsx

/Users/cameron_taggart/Projects/SourceLink4/build.fsx(1,1): error FS0078: Unable to find the file 'NuGet.Core.dll' in any of
 /Library/Frameworks/Mono.framework/Versions/3.2.6/lib/mono/4.5
 /Users/cameron_taggart/Projects/SourceLink4
 /Library/Frameworks/Mono.framework/Versions/3.2.6/lib/mono/4.0/