Removed unnecessary test file copies in CMake configuration.

tests/CMakeLists.txt

@@ -13,12 +13,10 @@ set(libraries
 	plasp
 )
 
-file(COPY data DESTINATION ${CMAKE_BINARY_DIR})
-
 add_executable(${target} ${core_sources})
 target_link_libraries(${target} ${libraries})
 
 add_custom_target(run-tests
 	COMMAND ${CMAKE_BINARY_DIR}/bin/tests
 	DEPENDS ${target}
-	WORKING_DIRECTORY ${CMAKE_BINARY_DIR})
+	WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}/tests)