Remove PostFile() from session; refine cmake files; replace final with override.

unittest/CMakeLists.txt

@@ -10,7 +10,7 @@ set(UT_SRCS
 set(UT_TARGET_NAME webcc_unittest)
 
 # Common libraries to link.
-set(UT_LIBS webcc ${Boost_LIBRARIES} "${CMAKE_THREAD_LIBS_INIT}")
+set(UT_LIBS webcc gtest ${Boost_LIBRARIES} "${CMAKE_THREAD_LIBS_INIT}")
 
 if(WEBCC_ENABLE_SSL)
     set(UT_LIBS ${UT_LIBS} ${OPENSSL_LIBRARIES})
@@ -34,6 +34,6 @@ if(UNIX)
 endif()
 
 add_executable(${UT_TARGET_NAME} ${UT_SRCS})
-target_link_libraries(${UT_TARGET_NAME} webcc gtest ${UT_LIBS})
+target_link_libraries(${UT_TARGET_NAME} ${UT_LIBS})
 
 add_test(${UT_TARGET_NAME} ${UT_TARGET_NAME})

unittest/rest_service_manager_unittest.cc

@@ -7,7 +7,7 @@
 class MyRestService : public webcc::RestService {
 public:
   void Handle(const webcc::RestRequest& request,
-              webcc::RestResponse* response) final {
+              webcc::RestResponse* response) override {
     response->status = webcc::Status::kOK;
   }
 };