Simplify management of init defaults

Remove the quite useless `$init_defaults` hash from
`elasticsearch::params` and set the class parameter
`$elasticsearch::init_defaults` to undef by default.

The values in `$elasticsearch::params::init_defaults` are hardcoded in
the init script anyway, no need to also set them in the defaults file.
Instead let the defaults file only contain parameters the user wants to
override. These are supplied via the class parameter
`$elasticsearch::init_defaults` and end up in the defaults file.

This obsoletes/fixes #63.
Merge pull request #64 from antaflos/simplify_init_defaults

Simplify management of init defaults
Fix for elasticsearch/puppet-elasticsearch#65.
Merge pull request #66 from bodgit/docs

Fix for elasticsearch/puppet-elasticsearch#65.
allow creation of data directory
Merge pull request #68 from jlambert121/datadir

allow creation of data directory
Fail early when package version and package_url are defined
Update for release 0.2.1
Important update

- Ensure all exec resource names are unique for this module
  If using the Logstash module with this one it will fail
- Update spec tests
- Add spec tests for plugin define
update to 0.2.2
Fixed broken dependency because of rename
Move pgk-source higher so we can re-use that variable
fixed typo in template test
Merge pull request #72 from cdenneen/patch-1

Fixed broken dependency because of rename
Adding repo management option
Update spec testing and implement coverage testing
Adding puppet 3.4.x testing
Improve testing and coverage report
Improve spec testsing some more by testing the relationships between classes.
Update changelog