Added tools/boost_install and libs/headers manual init to CI jobs.

appveyor.yml

@@ -55,12 +55,14 @@ install:
   - cd ..
   - git clone -b %BOOST_BRANCH% https://github.com/boostorg/boost.git boost-root
   - cd boost-root
+  - git submodule init libs/headers
   - git submodule init libs/assert
   - git submodule init libs/config
   - git submodule init libs/predef
   - git submodule init libs/static_assert
   - git submodule init libs/type_traits
   - git submodule init tools/build
+  - git submodule init tools/boost_install
   - git submodule update
   - xcopy /s /e /q %APPVEYOR_BUILD_FOLDER% libs\core
   - cmd /c bootstrap