GET strcuture

Build out infrastructure for get requests (along with the first couple).

This includes changing the request engine from Volley to OKHTTP due to issues get Volley's callbacks to call back.

Lambdas/Lists/List/src/ListGET.java

@@ -0,0 +1,12 @@
+import com.amazonaws.services.lambda.runtime.Context;
+import com.amazonaws.services.lambda.runtime.RequestHandler;
+
+import java.util.Map;
+
+public class ListGET implements RequestHandler<Map<String,Object>, Object> {
+
+    public Object handleRequest(Map<String, Object> inputMap, Context unfilled) {
+        return BasicHandler.handleRequest(inputMap, unfilled, ListGetter.class);
+    }
+
+}