specs: test Puppet 3.1.0, only set libdir where required

Bump puppetlabs_spec_helper for #18165, fixes 3.1.0 libdir initialisation
Rename 'licence' so Puppet Forge finds it
Implement prefetch in host provider
Implement prefetch in mailalias provider
sshd_config: Simplify type and provider with key as namevar
Ignore rvm/rbenv configs
Remove symlinks from docs/, fixes #25
Link to examples from README
Release 0.5.2
spec/lib/augeas_spec/fixtures.rb: Accept more than one resource in apply() and apply!()
sshd_config: Add tests for duplicated resources
Revert "sshd_config: Simplify type and provider with key as namevar"

This reverts commit c896cb308a4a5812f7cb62e187f54d82fc50e9a2.
sshd_config: add examples using multiple resources with keys

Fixes #27
Release 0.5.3
Update rubygems source to URL
Add .fixtures.yml
Replace librarian-puppet with puppetlabs_spec_helper's .fixtures.yml
Remove librarian-puppet and PMT from Travis setup
Leave setting modulepath to rspec-puppet
kernel_parameter: use EFI GRUB legacy config if present

Fixes #30