Move the test step to after_script

Author: asbjornu

.travis.yml

@@ -8,4 +8,5 @@ install:
   - nuget install NUnit.Runners -Version 3.2.1 -OutputDirectory ./src/packages
 script:
   - xbuild "./src/GitVersion.sln" /property:Configuration="Debug" /verbosity:detailed
+after_script:
   - mono --debug --runtime=v4.0.30319 ./src/packages/NUnit.ConsoleRunner.3.2.1/tools/nunit3-console.exe ./src/GitVersionTask.Tests/bin/Debug/GitVersionTask.Tests.dll ./src/GitVersionCore.Tests/bin/Debug/GitVersionCore.Tests.dll ./src/GitVersionTask.Tests/bin/Debug/GitVersionTask.Tests.dll ./src/GitVersionExe.Tests/bin/Debug/GitVersionExe.Tests.dll -where "cat != NoMono"