Add contracts directory to regression tests run via CMake

tautschnig · tautschnig · commit c2af333e854f · 2018-10-18T11:45:21.000Z
The Makefile had this directory added in d49ea09, but this wasn't the case for CMake.
diff --git a/regression/CMakeLists.txt b/regression/CMakeLists.txt
@@ -43,3 +43,4 @@ add_subdirectory(goto-cc-cbmc)
 add_subdirectory(cbmc-cpp)
 add_subdirectory(goto-cc-goto-analyzer)
 add_subdirectory(systemc)
+add_subdirectory(contracts)
