fix remove_locales condition

.travis.yml

@@ -15,7 +15,7 @@ install:
   - pip install pyyaml coveralls flake8 flake8-import-order doc8
   - if [[ $TRAVIS_PYTHON_VERSION != 2* ]]; then pip install sphinx; fi
   - pip install .
-  - if [[ $REMOVE_LOCALES ]]; then sudo rm -rf /usr/lib/locale/* ; fi
+  - if [[ $REMOVE_LOCALES = "true" ]]; then sudo rm -rf /usr/lib/locale/* ; fi
 script:
   - if [[ $TRAVIS_PYTHON_VERSION != nightly ]]; then flake8 .; fi
   - if [[ $TRAVIS_PYTHON_VERSION != 2* ]]; then doc8 $(git ls-files '*.rst'); fi