Read server port from config

Summary: Set default server port in base config and use that if not set elsewhere.

Test Plan:
  lein test

Reviewers: #standard_treasury, keith

Reviewed By: #standard_treasury, keith

Differential Revision: http://phabricator.corp.standardtreasury.com/D3780

resources/conf/base.edn

@@ -0,0 +1,3 @@
+{
+  :port 5000
+}

src/clams/app.clj

@@ -41,7 +41,7 @@
     (when (nil? @server)
       (conf/load!)
       (let [middleware (:middleware opts)
-            port       (get opts :port 5000)]
+            port       (conf/get :port)]
         (reset! server (httpkit/run-server (app app-ns middleware) {:port port}))))))
 
 (defn stop-server

src/clams/conf.clj

@@ -33,7 +33,8 @@
 
 (defn load!
   []
-  (reset! full-conf (merge (read-config "default")
+  (reset! full-conf (merge (read-config "base")
+                           (read-config "default")
                            (read-env))))
 
 (defn unload!

test/clams/test/conf_test.clj

@@ -43,3 +43,7 @@
   (is (= (conf/get :database-url) "sql://dev.fake:1234/foobar"))
   (is (= (conf/get-all) {:database-url "sql://dev.fake:1234/foobar"
                          :log-level    :debug})))
+
+(deftest base-test
+  (conf/load!)
+  (is (= (conf/get :port) 5000)))