oops, yaml syntax

Author: radix

.travis.yml

@@ -11,10 +11,10 @@ install:
     - pip install -r dev-requirements.txt
     - pip install sphinx sphinx_rtd_theme
     # black isn't installing on pypy3, so just skip it
-    - [ "$TRAVIS_PYTHON_VERSION" != "pypy3"] && pip install black
+    - '[ "$TRAVIS_PYTHON_VERSION" != "pypy3"] && pip install black'
 script:
     - flake8
-    - [ "$TRAVIS_PYTHON_VERSION" != "pypy3"] && black --check .
+    - '[ "$TRAVIS_PYTHON_VERSION" != "pypy3"] && black --check .'
     - pytest
     - make doc