Travis: add 3.7 testing
Travis: remove deploy to testpypi since it's broken
Travis: cherry-pick change to declarative APT
From efb9572
Removed pngquant
Travis: Remove linux_before_install.sh
Eliminate Homebrew autobrewing
Travis: add 3.7 testing
Travis: remove deploy to testpypi since it's broken
Travis: cherry-pick change to declarative APT
From efb9572
Removed pngquant
Travis: Remove linux_before_install.sh
Eliminate Homebrew autobrewing