[Travis] Make builds a bit faster

[ikesyo]

• Disable static analysis during build
• Don't generate debug symbols

[dmcrodrigues]

This won't help the build times, on the contrary, but shouldn't we also build tvOS and watchOS targets? And probably create a test target for tvOS?

[mdiep]

Thanks @ikesyo!

but shouldn't we also build tvOS and watchOS targets? And probably create a test target for tvOS?

Yeah, those would be great to add to the Travis matrix!

[dmcrodrigues]

Cool, I can help with that.