Move download-boost-snapshot.py into ci directory

Because __boost_check_library__ is complaining about it.

.appveyor.yml

@@ -18,7 +18,7 @@ environment:
 install:
   - set BOOST_ROOT=c:\projects\boost
   - cd c:\projects\
-  - python %APPVEYOR_BUILD_FOLDER%\build\download-boost-snapshot.py master
+  - python %APPVEYOR_BUILD_FOLDER%\ci\download-boost-snapshot.py master
   - rd /s /q %BOOST_ROOT%\boost\unordered
   - cd %BOOST_ROOT%\tools\build
   - cmd /c bootstrap

.travis.yml

@@ -70,7 +70,7 @@ before_script:
         echo "Downloading ${download_url}"
         mkdir $HOME/download
         cd $HOME/download
-        python ${TRAVIS_BUILD_DIR}/build/download-boost-snapshot.py $snapshot
+        python ${TRAVIS_BUILD_DIR}/ci/download-boost-snapshot.py $snapshot
         mv * ${BOOST_ROOT}
     - rm -r ${BOOST_ROOT}/boost/unordered
     - cd ${BOOST_ROOT}/tools/build