(GH-272) Fail gracefully for Puppet Lint configuration

Previously the Puppet-Lint configuration could raise an error, thereby stopping
any puppet lint rules from working.  This was due to puppet-lint.rc files
containing command params which were invalide due to puppet-lint plugin gems
not being loaded e.g. --no-trailing_comma-check

This commit changes the document validator to use the default configuration if
an error occurs loading the configuration.

Author: glennsarti

lib/puppet-languageserver/manifest/validation_provider.rb

@@ -45,7 +45,12 @@ def self.validate(session_state, content, options = {})
         if module_root.nil?
           linter_options = PuppetLint::OptParser.build
         else
-          Dir.chdir(module_root.to_s) { linter_options = PuppetLint::OptParser.build }
+          begin
+            Dir.chdir(module_root.to_s) { linter_options = PuppetLint::OptParser.build }
+          rescue OptionParser::InvalidOption => e
+            PuppetLanguageServer.log_message(:error, "(#{name}) Error reading Puppet Lint configuration.  Using default: #{e}")
+            linter_options = PuppetLint::OptParser.build
+          end
         end
         linter_options.parse!([])