Add @FunctionalSpringBootTest and mini web server

User can run a minimal HTTP app using an app that is a Function
or an ApplicationContextInitializer. Can also test using
@FunctionalSpringBootTest in place of @SpringBootTest.

Add some tests and documentation for functional beans

Make server.address configurable

README.adoc

@@ -183,16 +183,10 @@ http://eclipse.org/m2e/[m2eclipse] eclipse plugin for maven support. Other IDEs
 should also work without issue as long as they use Maven 3.3.3 or better.
 
 ==== Importing into eclipse with m2eclipse
-
 We recommend the http://eclipse.org/m2e/[m2eclipse] eclipse plugin when working with
 eclipse. If you don't already have m2eclipse installed it is available from the "eclipse
 marketplace".
 
-Also, you will need to install Kotlin plug-in from the "eclipse marketplace" to ensure projects 
-that depend on Kotlin complile under `m2eclipse` plugin (mentioned above). 
-
-NOTE: If you still see compile errors after installing Kotlin plugin, simply right-click on the project with error and _remove_ and then _add_ Kotlin Nature via ***Configure Kotlin*** feature. 
-
 NOTE: Older versions of m2e do not support Maven 3.3, so once the
 projects are imported into Eclipse you will also need to tell
 m2eclipse to use the right profile for the projects.  If you
@@ -260,4 +254,4 @@ added after the original pull request but before a merge.
   other target branch in the main project).
 * When writing a commit message please follow http://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html[these conventions],
   if you are fixing an existing issue please add `Fixes gh-XXXX` at the end of the commit
-  message (where XXXX is the issue number).
+  message (where XXXX is the issue number).