Allow double quotes for puppet supported escape sequences

add support for \$ \" \' \r (\t \n already supported) escape
sequences.

This is to follow:
 http://docs.puppetlabs.com/puppet/2.7/reference/lang_datatypes.html#double-quoted-strings

While puppet supports \\ and \s, both are replaced with normal characters
that lint otherwise should look for.

These are necessary to support confusing escape sequens that end up being
passed to downstream commands and the like. Making propper use double
quotes but preventing lint from generating false warnings.

Signed-off-by: Andrew Woodward <awoodward@mirantis.com>
Merge branch 'master' of https://github.com/xarses/puppet-lint into xarses-master

Conflicts:
	spec/puppet-lint/plugins/check_strings/double_quoted_strings_spec.rb