Do not attempt to run python2 tests on osx.
Homebrew updating was taking a long time, causing timeouts.
Reduced the number of homebrew formulas to cut down install time.
Some of the removed ones are already provided in the osx image.
osx_image updated because only the newer ones work without
travis's homebrew addon flag 'update: true'
https://changelog.travis-ci.com/xcode-11-3-1-xcode-11-2-1-xcode-11-1-and-xcode11-images-updated-142286
Config updated with the help of live validator:
https://config.travis-ci.com/explore
Added sudo flag "-H" to "sudo pip*" as pip suggests.
Trying to make use of cached of $HOME/perl_modules.
android: Install p4a using pip
Add 'set -e' to sh scripts, they must stop upon any error
README.md: kivy does not specifically require python2
android: Overhaul initialization scripts
android: Simplify apk build scripts by using the 'common' file
Merge the scripts cardconv and cardsetsgiftobmp
android: Fix startup script shebang to python3
android: Simplify mkkeystore and ignore the keystore file
android: Fix up debian prerequisites
The package cython (as opposed to cython3) even caused me to produce
an apk that did not start (TypeError: must be str, not bytes).
Android SDK requires java8; install and set as the default.
The build processes complained about lld and libtinfo5; added in.
mercurial (or hg) is seemingly unused.
The pip pcakges were needed by android/initsdk.py which is gone.
android: Ensure that the html files are built
