Use clang on travis with Android

[tomaka]

Follow-up of #633

[tomaka]

The travis failure is due to the fact that the inline assembly uses thumb-2 instructions.

According to this page, we are supposed to use the thumb- targets, which makes sense to me.

I'm not sure why it works for gcc, but I suppose that gcc doesn't follow the same system.
I'm also confused as to how Parity successfully compiles despite the fact that is uses clang and a git version of ring (so no precompiled header).

[coveralls]

Coverage remained the same at ?% when pulling 7b26072 on tomaka:clang-android-travis into ee13e73 on briansmith:master.

[briansmith]

According to this page, we are supposed to use the thumb- targets, which makes sense to me.

Let's change this PR to use the thumb targets so the CI build step passes.

[briansmith]

Let's change this PR to use the thumb targets so the CI build step passes.

Never mind,I don't think that's the right solution. I think I have a fix. Working on it.

[briansmith]

I'm also confused as to how Parity successfully compiles despite the fact that is uses clang and [...]

I bet Parity is using a newer version of the NDK and/or clang or whatever and I bet that is the solution here. Any tips on how to get ring's CI to work more like Parity's?

[tomaka]

Tests seem to pass on travis 🎉

[briansmith]

Thanks! Merged.