Fixed compile issue of unit tests
Fixed compile issue of unit tests

The guide curve tests used the coons c2 feature,
which is not available in standard oce/occt. 
This commit checks, if the feature is available
or not. This should fix the travis build.
DLR-SC/tigl,DLR-SC/tigl,DLR-SC/tigl,DLR-SC/tigl,DLR-SC/tigl,DLR-SC/tigl