The GCP initialization pulls credentials for
talking to GCP. We want that to only happen
when fully required and thus want the GCP-related
objects lazily instantiated.
* Refactor Guice initialization
Builders for various module collections
Revise the extensions loader
Injector builders for server startup
Move Hadoop init to indexer
Clean up server node role filtering
Calcite test injector builder
* Revisions from review comments
* Build fixes
* Revisions from review comments
* Move GCP to a core extension
* Don't provide druid-core >.<
* Keep AWS and GCP modules separate
* Move AWSModule to its own module
* Add aws ec2 extension and more modules in more places
* Fix bad imports
* Fix test jackson module
* Include AWS and GCP core in server
* Add simple empty method comment
* Update version to 15
* One more 0.13.0-->0.15.0 change
* Fix multi-binding problem
* Grep for s3-extensions and update docs
* Update extensions.md