Fixup brew.

Author: ionelmc

.travis.yml

@@ -100,6 +100,7 @@ before_install:
   - lsb_release -a || true
   - |
     if [[ $TRAVIS_OS_NAME == 'osx' ]]; then
+      brew update-reset
       [[ $TOXENV =~ py3 ]] && brew upgrade python
       [[ $TOXENV =~ py2 ]] && brew install python@2
       export PATH="/usr/local/opt/python/libexec/bin:${PATH}"

ci/templates/.travis.yml

@@ -45,6 +45,7 @@ before_install:
   - lsb_release -a || true
   - |
     if [[ $TRAVIS_OS_NAME == 'osx' ]]; then
+      brew update-reset
       [[ $TOXENV =~ py3 ]] && brew upgrade python
       [[ $TOXENV =~ py2 ]] && brew install python@2
       export PATH="/usr/local/opt/python/libexec/bin:${PATH}"