explicitly depend on Akka HTTP

[eed3si9n]

Ref https://discuss.lightbend.com/t/no-configuration-setting-found-for-key-decode-max-size/2738
Fixes #103
Fixes lagom/lagom#1652

explicitly depend on Akka HTTP to bring in 10.1.5 to avoid No configuration setting found for key 'decode-max-size'.

[TimMoore]

So I guess this means that it breaks compatibility with Lagom 1.4.x, but it didn't actually change the Lagom dependency. I'm not sure that this is actually the best solution. Wasn't the problem fixed upstream in Akka HTTP?

[TimMoore]

Here's where that was fixed: akka/akka-http#2307

AFAIK reactive-lib did not need this change. @renatocaval can you comment?

[octonato]

Lagom 1.4.9 is using akka-http 10.0.14 and is affected by the decode-max-size property issue because that config was backported to akka-http 10.0.14.

We need a reactive-lib version tailored for Lagom 1.4.x, depending on akka-http 10.0.14 and akka-management 0.20.
Or even better, reactive-lib should not need to depend directly on akka-http, but on akka-management 0.21 that itself should depends on akka-http 10.0.14.

Then, for Lagom 1.5.x, we need it depending on akka-management 0.50 and transitively on akka-http 10.1.6.

[eed3si9n]

I tested with online auction 1.4.x branch and looked ok, but I'd be happy to bump Akka Management when 0.21.0 is available.

[eed3si9n]

For now should I depend on Akka HTTP 10.0.14 so it's aligned with Lagom 1.4.x at least?

[octonato]

There is already an akka-http 10.0.15.

So yea, if we plan to cut a release for Lagom 1.4.x based on akka-management 0.20, then better to depend on akka-http 10.0.15. Lagom 1.4.10 will be based on 10.0.15.

I'm not sure if we are going to have an akka-mgnt 0.21 with 10.0.15. (cc @chbatey / @patriknw)