Set up a continuous integration build for Android

[iphydf]

We need at least one Android build (perhaps arm32) on Travis so we know we're not breaking stuff for that platform.

[iphydf]

@zoff99 is this something you'd be interested in setting up on CircleCI? If so, feel free to assign this bug to yourself.

[zoff99]

ok. i will work on it. could take a while ..

[iphydf]

Thanks, no hurry :)

[Zer0-One]

I also needed android builds. @zoff99 if you need some help, lmk.

[zoff99]

you need just the libs (*.so) right?
i already build it all from source for Antox-"new" so i should be able to make then soon

[GrayHatter]

arm builds are pretty trivial with cmake and a toolchain file

[zoff99]

what files do you want as a result? .so? .a?
is it just for checking that the build works, or does somebody want to use those libs on android?

[GrayHatter]

@zoff99 we have a build server that does binaries for us. We want to make sure that the arm version will still build with ANY change to the code base.

We don't need the artefacts, only to know if it builds at all.

[zoff99]

ok almost done. but has errors now.
see #457