fix dependencies / test includes / mod includes

hi jez,

i've made some changes to the build that appear to fix the tests. 

##### build.gradle
always use provided for jars that are part of other modules (they should be provided at runtime by vertx). if you use compiled then you end up with two copies of the classes

##### GroovyIntegrationTests
add includes="" secret receipe to the unit-test so it pulls in the module. this is how the test gets the module jars that are not included once you switch to provided. 

__this does not use rxVersion however, so its hard-coded to beta-1__ 

i'm not sure if there's a better way to do this - it seems brittle to me, i think groovy support needs a better solution for integration tests.

i havent tested the module itself, but i've updated mod.json to add the includes reference so it should pull in the module automatically. lmk if its not working.

-peter