Try new android build environment on Travis CI

See https://github.com/travis-ci/travis-ci/issues/1395
Translated using Weblate (Korean)

Currently translated at 0% (0 of 0 strings)

Created new translation.
Translated using Weblate (Korean)

Currently translated at 100.0% (74 of 74 strings)
add v to version
Translated using Weblate (Dutch)

Currently translated at 100.0% (74 of 74 strings)
Merge remote-tracking branch 'origin/master'
sync buildtime trend in after_script
add newlines
translated to Korean, thanks to Cho Bkwon
Translated using Weblate (Spanish)

Currently translated at 93.2% (69 of 74 strings)
Translated using Weblate (Spanish)

Currently translated at 94.5% (70 of 74 strings)
Translated using Weblate (Spanish)

Currently translated at 95.9% (71 of 74 strings)
Translated using Weblate (Spanish)

Currently translated at 97.2% (72 of 74 strings)
Translated using Weblate (Spanish)

Currently translated at 100.0% (74 of 74 strings)
Translated using Weblate (Catalan)

Currently translated at 0% (0 of 0 strings)

Created new translation.
Translated using Weblate (Japanese)

Currently translated at 0% (0 of 0 strings)

Created new translation.
add J.S.Sebastian as a translator for Spanish [skip ci]
display in About activity when app was built
Translated using Weblate (Korean)

Currently translated at 100.0% (74 of 74 strings)
Translated using Weblate (Spanish)

Currently translated at 100.0% (74 of 74 strings)