Minor refactorings and code style changes (#807)

* Made minor changes in some patterns such as removed throws clause where not needed, changed incorrect order of arguments in assertEquals

* Minor refactorings and code style changes. 1) Removed several use of raw types 2) Removed unnecessary throws clauses 3) Used lambda expressions wherever applicable 4) Used apt assertion methods for readability 5) Use of try with resources wherever applicable 6) Corrected incorrect order of assertXXX arguments

* Removed unused import from Promise

* Addressed review comments

* Addressed checkstyle issue

chain/src/test/java/com/iluwatar/chain/OrcKingTest.java

@@ -43,7 +43,7 @@ public class OrcKingTest {
   };
 
   @Test
-  public void testMakeRequest() throws Exception {
+  public void testMakeRequest() {
     final OrcKing king = new OrcKing();
 
     for (final Request request : REQUESTS) {