Re-enable compiler flag -Werror (warnings are errors)

CMakeLists.txt

@@ -271,7 +271,7 @@ if(_LINTING)
     add_compiler_flag("-Wall")
     add_compiler_flag("-Wextra")
     add_compiler_flag("-pedantic")
-    # add_compiler_flag("-Werror") # removed until issue #71 is resolved
+    add_compiler_flag("-Werror") # removed until issue #71 is resolved
 
     message(STATUS "PEDANTIC_CMAKE_CXX_FLAGS: [${PEDANTIC_CMAKE_CXX_FLAGS}]")
     set(TARGET_LINKAHEAD_COMPILE_FLAGS "${TARGET_LINKAHEAD_COMPILE_FLAGS} ${PEDANTIC_CMAKE_CXX_FLAGS}")