check for the existence of a opmmodule_prepare target

if it exists, add this as a dependecy for satellites

cmake/Modules/OpmSatellites.cmake

@@ -289,6 +289,9 @@ macro(opm_add_test TestName)
       add_executable("${CURTEST_EXE_NAME}" ${CURTEST_EXCLUDE_FROM_ALL} ${CURTEST_SOURCES})
       target_link_libraries (${CURTEST_EXE_NAME} ${CURTEST_LIBRARIES})
 
+      if(TARGET ${opm}_prepare)
+        add_dependencies("${CURTEST_EXE_NAME}" ${opm}_prepare)
+      endif()
       if(CURTEST_DEPENDS)
         add_dependencies("${CURTEST_EXE_NAME}" ${CURTEST_DEPENDS})
       endif()