remove OCE from CMake, it is unmaintained

fixes aleutgeb#1

(see also aleutgeb/STEPToMesh#10 and aleutgeb/STEPToXSection#6)

Author: jmairboeck

src/CMakeLists.txt

@@ -55,8 +55,7 @@ endif()
 
 set(CMAKE_PREFIX_PATH "${OPENCASCADE_PREFIX};${CMAKE_PREFIX_PATH}")
 
-find_package(OpenCASCADE)
-find_package(OCE)
+find_package(OpenCASCADE REQUIRED)
 
 if(OpenCASCADE_WITH_TBB)
 	set(TBB_LIBRARY_PREFIX "${OPENCASCADE_PREFIX}/tbb_2017.0.100/lib/intel64/vc14" CACHE PATH "TBB library directory")