Create reverse compatible constructors

src/main/java/com/jagrosh/discordipc/entities/Callback.java

@@ -35,7 +35,7 @@ public class Callback
  */
  public Callback()
  {
- this(null, null);
+ this((Consumer<Packet>) null, null);
  }
 
  /**
@@ -64,6 +64,25 @@ public Callback(Consumer<Packet> success, Consumer<String> failure)
  this.failure = failure;
  }
 
+ /**
+ * @param success The Runnable to launch after a successful process.
+ * @param failure The Consumer to launch if the process has an error.
+ */
+ @Deprecated
+ public Callback(Runnable success, Consumer<String> failure)
+ {
+ this(p -> success.run(), failure);
+ }
+
+ /**
+ * @param success The Runnable to launch after a successful process.
+ */
+ @Deprecated
+ public Callback(Runnable success)
+ {
+ this(p -> success.run(), null);
+ }
+
  /**
  * Gets whether or not this Callback is "empty" which is more precisely
  * defined as not having a specified success {@link Consumer} and/or a