Drop BUILD_TESTING option from CMakeLists.txt

Not needed as it's added automatically by CTest.

Author: valgur

CMakeLists.txt

@@ -13,7 +13,6 @@ message (STATUS "${PROJECT_NAME} version ${URDF_VERSION}")
 include(GNUInstallDirs)
 
 option(BUILD_APPS "Build applications" ON)
-option(BUILD_TESTING "Build tests" OFF)
 option(USE_VENDORED_DEPS "Use vendored dependencies" ON)
 option(APPEND_PROJECT_NAME_TO_INCLUDEDIR
   "When ON headers are installed to a folder ending with an extra ${PROJECT_NAME}. \