Fix race condition in httpd install and config

Add necessary dependency/ordering hints to the httpd_mod
custom type so that httpd modules are installed before
they're needed rather than later, and so that httpd
service won't be loaded until Apache module dependencies
are in place.

Change-Id: I787c3e6cf50099bdba1fff1100d9ddbfc4de4812

manifests/init.pp

@@ -403,26 +403,31 @@ class zuul (
   if ! defined(Httpd_mod['rewrite']) {
     httpd_mod { 'rewrite':
       ensure => present,
+      before => Service['httpd'],
     }
   }
   if ! defined(Httpd_mod['proxy']) {
     httpd_mod { 'proxy':
       ensure => present,
+      before => Service['httpd'],
     }
   }
   if ! defined(Httpd_mod['proxy_http']) {
     httpd_mod { 'proxy_http':
       ensure => present,
+      before => Service['httpd'],
     }
   }
   if ! defined(Httpd_mod['cache']) {
     httpd_mod { 'cache':
       ensure => present,
+      before => Service['httpd'],
     }
   }
   if ! defined(Httpd_mod['cgid']) {
     httpd_mod { 'cgid':
       ensure => present,
+      before => Service['httpd'],
     }
   }
 
@@ -431,6 +436,7 @@ class zuul (
       if ! defined(Httpd_mod['mem_cache']) {
         httpd_mod { 'mem_cache':
           ensure => present,
+          before => Service['httpd'],
         }
       }
     }
@@ -438,6 +444,7 @@ class zuul (
       if ! defined(Httpd_mod['cache_disk']) {
         httpd_mod { 'cache_disk':
           ensure => present,
+          before => Service['httpd'],
         }
       }
     }