Use plugable not authorized page

[lukestephenson]

Previously was hardcoded to the securesocial implementation. Now allowing
custom not authorized pages to be rendered.

Fixes #499

---

Note that I've tested this manually by publishing and using from my application which is using securesocial. I wasn't able to get the securesocial unit tests running. Invoking sbt test with a fresh clone of master resulted in compilation errors in the sample projects. Can you please document how the tests should be run.

eg

[error] C:\developer\workspace\securesocial\samples\scala\demo\test\ApplicationSpec.scala:6: object testkit is not a member of package securesocial
[error] import securesocial.testkit.WithLoggedUser

Even if I limit to the core tests with sbt "project core" test some tests fail to pass? Is this correct or something broken in my setup?

[info] GoogleLoginSpec
[info]
[info] an application using secure social should
[info] x log a valid google user
[error]    'Some(http:///login)' is not equal to 'Some(/)' (GoogleLoginSpec.scala:61)

Thanks

[lloydmeta]

👍 for this.

[jaliss]

thanks @lukestephenson!