Install newer Firefox in hopes to avoid intermittent CI failures
Install newer Firefox in hopes to avoid intermittent CI failures

https://travis-ci.org/github/fetch/builds/383771737
https://travis-ci.org/github/fetch/builds/383770926
https://travis-ci.org/github/fetch/builds/383767274
https://travis-ci.org/github/fetch/builds/383767224

github/fetch,aleclarson/fetch