Add support for changing HostKey option

This is to make it possible to change the HostKey parameter in
sshd_config.

As the HostKey is hardcoded to the template now it is currently not
possible to connect using for example ssh-dss. This commit changes that
behaviour.
Release v3.18.0 - ability to specify custom templates
Add support for GSSAPIDelegateCredentials in ssh_config.

By default this only applies to Solaris 11.
Merge pull request #88 from ghoneycutt/GSSAPIDelegateCredentials_ssh_config_for_solaris11

Add support for GSSAPIDelegateCredentials in ssh_config.
Merge branch 'master' of github.com:ghoneycutt/puppet-module-ssh
Release v3.19.0 - Support GSSAPIDelegateCredentials in ssh_config
Release v3.19.1 - Bugfix: default GSSAPIDelegateCredentials to undef

This was previously set to undef everywhere except Solaris 11 which was
set incorrectly to 'yes'.
Merge pull request #89 from ghoneycutt/release_v3.19.1_bugfix_for_GSSAPIDelegateCredentials

Release v3.19.1 - Bugfix: default GSSAPIDelegateCredentials to undef
Support Puppet v3.7
Support puppet-lint v1
Support EL7

No actual code changes were needed to support EL7. Tests were updated
such that each supported release of EL is now tested.
Merge pull request #90 from ghoneycutt/el7

El7
Release v3.20.0 - Support EL7
Merge pull request #85 from diddi-/sshd_hostkey

Add support for changing HostKey option in sshd_config
Style fix - no functional changes
Merge pull request #91 from ghoneycutt/style_fix

Style fix - no functional changes
Release v3.21.0 - Add ability to specify HostKey in sshd_config