Add Timber 4.0.1

[Bill Zangardi]

https://github.com/JakeWharton/timber

[Markus Maga]

Timber shouldn't require any additional proguard rules?

And for required proguard rules it contains a consumer-proguard-rules.pro (link) already including the necessary rules for you :)

Timber proguard:
-dontwarn org.jetbrains.annotations.**

Update:
The consumer-proguard-rules.pro in timber was added in 4.1.0, my bad :)
So updating to 4.1.0 should solve the problem otherwise add the snippet above.

[Kevin Schultz]

Thanks @Flydiverny, that's really helpful. I think I'm going to close this, whenever a library has consumerProguard files that is the preferred solution. Although it requires an upgrade from 4.0.1 to 4.1.0 that doesn't look too onerous.