Enable CGAL on Travis + AppVeyor.

.appveyor.yml

@@ -36,7 +36,7 @@ build_script:
   # Tutorials and tests
   - mkdir build
   - cd build
-  - cmake -DCMAKE_BUILD_TYPE=%config% -DLIBIGL_WITH_COMISO=OFF -DLIBIGL_BUILD_PYTHON=OFF -G "Visual Studio 15 2017 Win64" ../
+  - cmake -DCMAKE_BUILD_TYPE=%config% -DLIBIGL_WITH_CGAL=ON -DLIBIGL_WITH_COMISO=OFF -DLIBIGL_BUILD_PYTHON=OFF -G "Visual Studio 15 2017 Win64" ../
   - set MSBuildLogger="C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll"
   - set MSBuildOptions=/v:m /p:Configuration=%config% /logger:%MSBuildLogger%
   - msbuild %MSBuildOptions% libigl.sln

.travis.yml

@@ -60,7 +60,7 @@ script:
 # Tutorials and tests
 - mkdir build
 - cd build
-- cmake -DCMAKE_BUILD_TYPE=$CONFIG -DLIBIGL_BUILD_TESTS=ON -DLIBIGL_BUILD_TUTORIALS=ON -DEMBREE_ISA_AVX=OFF -DEMBREE_ISA_AVX2=OFF -DEMBREE_ISA_AVX512SKX=OFF ../
+- cmake -DCMAKE_BUILD_TYPE=$CONFIG -DLIBIGL_WITH_CGAL=ON -DEMBREE_ISA_AVX=OFF -DEMBREE_ISA_AVX2=OFF -DEMBREE_ISA_AVX512SKX=OFF ../
 - make -j 2
 - ctest --verbose
 - ccache --show-stats