Add Gemfile and puppet 4 checks

In anticipation of puppet 4, start trying to deal with puppet 4 things
that can be helpfully predicted by puppet lint plugins. Also fix lint
errors caught by the puppet-lint-empty_string-check and
puppet-lint-absolute_classname-check gems.

Change-Id: I923739c6997287509e75b37643ea0abe171a9faf

.gitignore

@@ -0,0 +1,2 @@
+Gemfile.lock
+.bundled_gems/

Gemfile

@@ -0,0 +1,30 @@
+source 'https://rubygems.org'
+
+group :development, :test do
+  gem 'puppetlabs_spec_helper', :require => false
+
+  gem 'metadata-json-lint'
+  # This is nice and all, but let's not worry about it until we've actually
+  # got puppet 4.x sorted
+  # gem 'puppet-lint-param-docs'
+  gem 'puppet-lint-absolute_classname-check'
+  gem 'puppet-lint-absolute_template_path'
+  gem 'puppet-lint-trailing_newline-check'
+
+  # Puppet 4.x related lint checks
+  gem 'puppet-lint-unquoted_string-check'
+  gem 'puppet-lint-empty_string-check'
+  gem 'puppet-lint-leading_zero-check'
+  gem 'puppet-lint-variable_contains_upcase'
+  gem 'puppet-lint-spaceship_operator_without_tag-check'
+  gem 'puppet-lint-undef_in_function-check'
+
+  if puppetversion = ENV['PUPPET_GEM_VERSION']
+    gem 'puppet', puppetversion, :require => false
+  else
+    gem 'puppet', '~> 3.0', :require => false
+  end
+
+end
+
+# vim:ft=ruby

manifests/init.pp

@@ -7,10 +7,10 @@ class gerritbot(
   $user,
   $channel_file,
   $vhost_name = $::fqdn,
-  $ssh_rsa_key_contents = '',
-  $ssh_rsa_pubkey_contents = '',
+  $ssh_rsa_key_contents = undef,
+  $ssh_rsa_pubkey_contents = undef,
 ) {
-  include pip
+  include ::pip
 
   package { 'gerritbot':
     ensure   => present,  # Pip upgrade is not working
@@ -80,7 +80,7 @@ class gerritbot(
     require => User['gerrit2'],
   }
 
-  if $ssh_rsa_key_contents != '' {
+  if $ssh_rsa_key_contents != undef {
     file { '/home/gerrit2/.ssh/gerritbot_rsa':
       owner   => 'gerrit2',
       group   => 'gerrit2',
@@ -91,7 +91,7 @@ class gerritbot(
     }
   }
 
-  if $ssh_rsa_pubkey_contents != '' {
+  if $ssh_rsa_pubkey_contents != undef {
     file { '/home/gerrit2/.ssh/gerritbot_rsa.pub':
       owner   => 'gerrit2',
       group   => 'gerrit2',