Increased open file limits on debian systems

This change is prompted by npm-based builds, which tends to open
many files due to the 'microlibrary' approach that many javascript
projects take. In particular, horizon's npm-based builds were
running into this limit- while the tests were executing well, the
file open limit was exceeded during report generation.

This patch ups the soft limit from 1024 to 4096, and the hard limit
from 4096 to 8192 on all debian systems.

Change-Id: I8fc4a23eb34da88f7076a4c1ef2ec4c975dc450e

modules/openstack_project/files/debian_limits.conf

@@ -0,0 +1,4 @@
+# Original 1024
+*                soft   nofile           4096
+# Original 4096
+*                hard   nofile           8192

modules/openstack_project/manifests/template.pp

@@ -334,6 +334,14 @@ class openstack_project::template (
       }
     }
 
+    file { '/etc/security/limits.d/60-nofile-limit.conf':
+      owner   => 'root',
+      group   => 'root',
+      mode    => '0644',
+      source  => 'puppet:///modules/openstack_project/debian_limits.conf',
+      replace => true,
+    }
+
     file { '/etc/apt/apt.conf.d/80retry':
       owner   => 'root',
       group   => 'root',