Method reference does not work anymore en 5.x

[TimoPtr]

On the previous version it was very nice to do something like that

.subscribe({}, Timber::e)

while using rxJava, but now the only workarround I found is

.subscribe({}, Forest::e)

[JakeWharton]

This is a consequence of the rewrite in Kotlin, yes. The 5.x version remains binary compatible with 4.x, but there are source-incompatible changes for both Java and Kotlin such as this one.

[TimoPtr]

I made a PR, to propose a solution to this issue. At Kolibree we do use a lot static references to Timber and the migration to 5.x is going to be very painful for use, but I can understand that it's not a very nice solution and you don't want to merge it to the trunk.

[TimoPtr]

@JakeWharton do you think it's an acceptable solution ?