Merge pull request #3 from cmbirk/master

add Project::createMilestone()

src/Rossedman/Teamwork/Project.php

@@ -138,6 +138,18 @@ public function milestones($args = null)
         return $this->client->get("$this->endpoint/$this->id/milestones", $args)->response();
     }
 
+    /**
+     * Create milestone associated with this project
+     * POST /projects/{project_id}/milestones.json
+     *
+     * @param $args
+     *
+     * @return mixed
+     */
+    public function createMilestone($args) {
+        return $this->client->post("$this->endpoint/$this->id/milestones", ['milestone' => $args])->response();
+    }
+
     /**
      * Tasklists
      * GET /projects/{project_id}/tasklists.json