Fix syntax error in metadata.json.

The author and module names in the dependencies
section of the metadata.json files shold be
separted with a "/" not a "-".
Make module work on CentOS and Red Hat.

The sysdig package requires the EPEL repository
on CentOS and Red Hat. The kernel-devel package is
also required.

Tested on CentOS 7.
Add Puppet version 3.7.0 to Travis tests.
Update CHANGELOG.
Merge pull request #1 from seanmalloy/master

Fix syntax error in metadata.json.