Add support for Play 2.6

[benmccann]

Context

Adds support for Play 2.6, which will soon be released. I'm a committer to Play and employee of LinkedIn

Contributor Checklist

• Review Contribution Guidelines
• Sign Gradle CLA
• [N/A] Link to Design Spec for changes that affect more than 1 public API (that is, not in an internal package) or updates to > 20 files
• Provide integration tests (under <subproject>/src/integTest) to verify changes from a user perspective
• Provide unit tests (under <subproject>/src/test) to verify logic
• Update User Guide, DSL Reference, and Javadoc for public-facing changes
• Ensure that tests pass locally: ./gradlew quickCheck :platformPlay:check

Gradle Core Team Checklist

• Verify design and implementation
• Verify test coverage and CI build status
• Verify documentation including proper use of @since and @Incubating annotations for all public APIs
• Recognize contributor in release notes

[big-guy]

Hey @benmccann. Thanks again for the PR. I'll be taking a look at this for the next release too. I'll let you know when I get back around to this.

[wsargent]

@big-guy @benmccann Play 2.6.0 is generally available as of today, so it'd be good to get this in.

[big-guy]

Hey @benmccann @wsargent, I started running this through our CI infrastructure.

Should there be a com.typesafe.play:run-support_2.11:2.6.0 published somewhere? I see one for M1 and M2, but nothing for anything later.
http://search.maven.org/#search%7Cgav%7C1%7Cg%3A%22com.typesafe.play%22%20AND%20a%3A%22run-support_2.11%22

I also checked the typesafe repos, JCenter and run-support_2.12, and didn't see a 2.6.0 version anywhere.

[benmccann]

I see there's a 2.10 version published on Maven. I'm guessing we don't publish 2.11 and 2.12 versions because that library is only used by our SBT plugin, which only runs Scala 2.10

[big-guy]

Ah, I didn't think about going down a version :)

It looks like the only part we actually use from that library is play.runsupport.AssetsClassLoader, so it may be easy for us to just provide our own copy of that class.

[benmccann]

@big-guy we can publish a 2.11 version of the library. Filed an issue in the Play tracker playframework/playframework#7687

[big-guy]

I attempted to just remove our dependency on runsupport: d489608

So we don't have to have a 2.11 version of it.

[benmccann]

Ok. That looks simpler anyway

[marcospereira]

playframework/twirl#136 was already merged and released. Maybe this can be updated to use play.japi.twirl.compiler.TwirlCompiler.

[benmccann]

Yep, that was the plan. I need #2062 to be merged first though

[big-guy]

I merged this into master (with some fixes for our integration tests). It'll be in 4.2

[benmccann]

Awesome. Thanks!