Only upload at master pushes for Travis CI

.travis.yml

@@ -134,6 +134,7 @@ script:
   - if [[ "$TRAVIS_OS_NAME" == "windows" ]] && [[ "$PLATFORM" == "mingw64" ]]; then $mingw64 ./.CI/travis_script.sh CFLAGS="-O3"; fi
 
 after_success:
+  - if [[ "$TRAVIS_PULL_REQUEST" != "false" ]] || [[ "$TRAVIS_BRANCH" != "master" ]]; then exit 0; fi
   - if [[ "$TRAVIS_OS_NAME" == "linux" ]] && [[ "$CC" == "gcc-4.8" ]]; then sh ./upload-to-bitbucket.sh tbeu $BBPASS /tbeu/downloads/downloads ExternData_$PLATFORM.tar.xz; fi
   - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then ./upload-to-bitbucket.sh tbeu $BBPASS /tbeu/downloads/downloads ExternData_$PLATFORM.tar.xz; fi
   - if [[ "$TRAVIS_OS_NAME" == "windows" ]]; then $msys2 curl -k --progress-bar -o nul -L -f -u "tbeu:$BBPASS" -F files=@"ExternData_$PLATFORM.tar.xz" "https://api.bitbucket.org/2.0/repositories/tbeu/downloads/downloads"; fi