[Travis,Appveyor] Disable pre-compiled headers for speedup.

.appveyor.yml

@@ -44,7 +44,7 @@ before_build:
 build_script:
   - mkdir build & cd build
   - conan install ..
-  - cmake .. -G "Ninja" -DCMAKE_BUILD_TYPE=%configuration% -DBUILD_SHARED_LIBS=ON -DOGS_EIGEN_DYNAMIC_SHAPE_MATRICES=ON
+  - cmake .. -G "Ninja" -DCMAKE_BUILD_TYPE=%configuration% -DBUILD_SHARED_LIBS=ON -DOGS_EIGEN_DYNAMIC_SHAPE_MATRICES=ON -DOGS_USE_PCH=OFF
   - cmake --build . --config %configuration%
 
 test_script:

.travis.yml

@@ -56,7 +56,7 @@ script:
   - if [ "$CASE" == "CHECK" ]; then git config core.whitespace -blank-at-eof; git diff --check `git merge-base origin/master HEAD` HEAD; fi
   - if [ "$CASE" != "CHECK" ]; then mkdir build; fi
   - if [ "$CASE" != "CHECK" ]; then cd build; fi
-  - if [ "$CASE" != "CHECK" ]; then cmake $CMAKE_ARGS -DOGS_LIB_BOOST=System -DOGS_LIB_VTK=System -DCMAKE_BUILD_TYPE=Debug ..; fi
+  - if [ "$CASE" != "CHECK" ]; then cmake $CMAKE_ARGS -DOGS_LIB_BOOST=System -DOGS_LIB_VTK=System -DOGS_USE_PCH=OFF -DCMAKE_BUILD_TYPE=Debug ..; fi
   - if [ "$CASE" != "CHECK" ]; then make -j 2; fi
   - if [ "$CASE" != "CHECK" ]; then make tests; fi