fix map.erb to work on Redhat 6 releases

[mbelscher]

Currently our team still requires support for RHEL and CentOS6.7 releases. This has a back level
ruby of 1.8.7 the map.erb doesn't compile correctly

erb -x -T '-' map.erb | ruby -c
-:17: syntax error, unexpected '|', expecting tCOLON2 or '[' or '.'
... @mappings.inject(0) { |l,(h)| h['key'].size > l ? h['key']....
^
-:17: syntax error, unexpected '}', expecting kEND
...size > l ? h['key'].size : l }

With the latest changes to Ran UT test. This is the relevant section and the final tally

nginx::resource::map
os-independent items
basic assumptions

  should contain File[/etc/nginx/conf.d/backend_pool-map.conf] with owner => "root", group => "root", mode => "0644", ensure => "file" and content =~ /map \$uri \$backend_pool/
map.conf template content
  when hostnames is true
    should contain File[/etc/nginx/conf.d/backend_pool-map.conf] with mode => "0644"
    should set hostnames
  when default is pool_a
    should contain File[/etc/nginx/conf.d/backend_pool-map.conf] with mode => "0644"
    should set default
  when mappings is {"foo"=>"pool_b", "bar"=>"pool_c", "baz"=>"pool_d"}
    should contain File[/etc/nginx/conf.d/backend_pool-map.conf] with mode => "0644"
    should contain ordered mappings when supplied as a hash
  when mappings is [{"key"=>"foo", "value"=>"pool_b"}, {"key"=>"bar", "value"=>"pool_c"}, {"key"=>"baz", "value"=>"pool_d"}]
    should contain File[/etc/nginx/conf.d/backend_pool-map.conf] with mode => "0644"
    should contain mappings in input order when supplied as an array of hashes
  when ensure => absent
    should contain File[/etc/nginx/conf.d/backend_pool-map.conf] with ensure => "absent"
  when mappings is a string

    should raise Puppet::Error with message matching /mappings must be a hash of the form { 'foo' => 'pool_b' }/

Finished in 2 minutes 24.4 seconds (files took 1.43 seconds to load)
864 examples, 0 failures

[wyardley]

Just FWIW, the README has "Ruby 1.9.3 or later (Support for Ruby-1.8.7 is not guaranteed. YMMV)."

I can think of some other things the module assumes (ordered hashes, for one) that are also not Ruby 1.8.7 friendly.

That said, the change is small and the tests pass, so I've merged this.