(SERVER-203) Update to clj-http-client 0.4.0

This commit updates Puppet Server to utilize puppetlabs/clj-http-client
version 0.4.0.
Merge pull request #282 from camlow325/maint/master/SERVER-203-update-to-clj-http-client-0-4-0

(SERVER-203) Update to clj-http-client 0.4.0