pip install --use-wheel" was deprecated. See https://pip.pypa.io/en/s…

…table/news/#deprecations-and-removals

ci/travis/before_install-osx.sh

@@ -42,6 +42,6 @@ curl --silent --show-error --retry 5 -O http://releases.numenta.org/pip/1ebd3cb7
 python get-pip.py --user pip setuptools wheel
 
 echo "Installing Python dependencies"
-pip install --use-wheel --user -r bindings/py/requirements.txt --quiet || exit
+pip install --user -r bindings/py/requirements.txt --quiet || exit
 
 pip install pycapnp==0.5.8 --user || exit