Bumps Hystrix to 1.5.1 and RxJava to 1.1.2

- Bump to RxJava 1.1.2. Upgrading to 1.1.1, saw test failures in
  `HystrixRequestCachingSpec` due to `ClassCastException`. I _think_ it
may be related to a bug that was fixed in 1.1.2
(ReactiveX/RxJava#3697).
- Changes expected behaviour in `RxErrorHandlingSpec` - exceptions thrown
 `onComplete` do not get propagated to `onError`.  Related to this change in RxJava
(ReactiveX/RxJava#3155), onComplete *must*
return normally. This change went was included in RxJava 1.0.15.
- Code snippets in `RxRatpack.java` updated due to `Observable.x` being
  renamed `Observable.extend` -
ReactiveX/RxJava#3423. Also part of RxJava 1.0.15

gradle/dependencies.gradle

@@ -22,8 +22,8 @@ ext {
     guava: "18.0",
     groovy: "2.4.3",
     pac4j: "1.8.5",
-    rxjava: "1.0.14",
-    hystrix: "1.4.3",
+    rxjava: "1.1.2",
+    hystrix: "1.5.1",
     jackson: "2.6.2",
     dropwizardMetrics: "3.1.1",
     pegdown: "1.5.0",

ratpack-rx/src/main/java/ratpack/rx/RxRatpack.java

@@ -309,7 +309,7 @@ public static <T> Promise<List<T>> promise(Observable<T> observable) throws Unma
    *
    *   public static void main(String[] args) throws Throwable {
    *     List<String> results = ExecHarness.yieldSingle(execution ->
-   *       new AsyncService().observe("foo").x(RxRatpack::promise)
+   *       new AsyncService().observe("foo").extend(RxRatpack::promise)
    *     ).getValue();
    *
    *     assertEquals(Arrays.asList("foo"), results);
@@ -437,7 +437,7 @@ public static <T> Promise<T> promiseSingle(Observable<T> observable) throws Unma
    *
    *   public static void main(String[] args) throws Throwable {
    *     String result = ExecHarness.yieldSingle(execution ->
-   *       new AsyncService().observe("foo").x(RxRatpack::promiseSingle)
+   *       new AsyncService().observe("foo").extend(RxRatpack::promiseSingle)
    *     ).getValue();
    *
    *     assertEquals("foo", result);
@@ -456,7 +456,7 @@ public static <T> Promise<T> promiseSingle(Observable<T> observable) throws Unma
    * public class Example {
    *   public static void main(String[] args) throws Throwable {
    *     String result = ExecHarness.yieldSingle(execution ->
-   *       Observable.<String>empty().singleOrDefault("foo").x(RxRatpack::promiseSingle)
+   *       Observable.<String>empty().singleOrDefault("foo").extend(RxRatpack::promiseSingle)
    *     ).getValue();
    *     assertEquals("foo", result);
    *   }
@@ -550,7 +550,7 @@ public static <T> TransformablePublisher<T> publisher(Observable<T> observable)
    *
    *   public static void main(String[] args) throws Throwable {
    *     List<String> result = ExecHarness.yieldSingle(execution ->
-   *       new AsyncService().observe("foo").x(RxRatpack::publisher).toList()
+   *       new AsyncService().observe("foo").extend(RxRatpack::publisher).toList()
    *     ).getValue();
    *     assertEquals("foo", result.get(0));
    *   }

ratpack-rx/src/test/groovy/ratpack/rx/RxErrorHandlingSpec.groovy

@@ -200,7 +200,7 @@ class RxErrorHandlingSpec extends RatpackGroovyDslSpec {
     thrownException == e
   }
 
-  def "on complete can throw"() {
+  def "on complete cannot throw"() {
     given:
     def e = new Exception("!")
 
@@ -213,7 +213,7 @@ class RxErrorHandlingSpec extends RatpackGroovyDslSpec {
 
     then:
     get()
-    thrownException == e
+    noExceptionThrown()
   }
 
   def "downstream handler can error"() {
@@ -338,7 +338,7 @@ class RxErrorHandlingSpec extends RatpackGroovyDslSpec {
     thrownException == e
   }
 
-  def "exception thrown by oncomplete throwns"() {
+  def "exception thrown by oncomplete is not re-thrown"() {
     given:
     def e = new Exception("!")
 
@@ -366,7 +366,7 @@ class RxErrorHandlingSpec extends RatpackGroovyDslSpec {
     }
 
     then:
-    thrownException == e
+      noExceptionThrown()
   }
 
 }