Running CI on MinGW

.appveyor.yml

@@ -49,15 +49,18 @@ build_script:
     # Building Boost.
     - bootstrap.bat
     - b2.exe headers
-    - b2.exe -j4 toolset=msvc address-model=64 architecture=x86 link=static --with-program_options --with-filesystem --with-system --with-test --with-atomic --with-thread --with-date_time --with-chrono --with-regex --with-random --with-context --with-coroutine stage
+    - b2.exe -j4 toolset=msvc,gcc address-model=64 architecture=x86 link=static --with-program_options --with-filesystem --with-system --with-test --with-atomic --with-thread --with-date_time --with-chrono --with-regex --with-random --with-context --with-coroutine stage
     - cd %APPVEYOR_BUILD_FOLDER%
     # Building examples.
     - qmake "BOOST_PATH=%BOOST%" BoostBook.pro
-    - nmake
 
 after_build:
 before_test:
 test_script:
+    - nmake
+    - python ./test.py
+    - nmake clean
+    - mingw32-make
     - python ./test.py
 
 after_test: