use chef 0.10.0 environments

* Replaces all occurrances of node app_environment attribute with
node.chef_environment in recipes.
* Still need to update readmes for using environments instead of roles.

Author: jtimberman

recipes/app_lb.rb

@@ -17,6 +17,8 @@
 # limitations under the License.
 #
 
+pool_members = search("node", "role:#{node['haproxy']['app_server_role']} AND chef_environment:#{node.chef_environment}") || []
+
 package "haproxy" do
   action :install
 end
@@ -33,8 +35,6 @@
   action [:enable, :start]
 end
 
-pool_members = search("node", "role:#{node['haproxy']['app_server_role']} AND app_environment:#{node['app_environment']}") || []
-
 template "/etc/haproxy/haproxy.cfg" do
   source "haproxy-app_lb.cfg.erb"
   owner "root"