Don't force certificate

Don't force certificates for early bootstrapping.
Add removal of files installed by the package

Some files are placed by the package which we don't use.
Lets remove them
[TESTING] Pin docker-api gem version
[TESTING] Add spec tests for file removal
Merge pull request #144 from elasticsearch/fix/files_removal

Add removal of files installed by the package
Merge pull request #140 from efontana/master

Don't force certificate
[TESTING] Fix spec tests after merging PR #140
[TESTING] Make use of our own docker images
added plugin name conventions

taken from the elasticsearch bin/plugin executable help text.
Merge pull request #148 from richtmat/patch-1

added plugin name conventions