Declare throws Exception in the interfaces for background functions. This saves users from having to catch checked exceptions and rethrow them as unchecked ones.

Fixes #21.

PiperOrigin-RevId: 304515456

Author: eamonnmcmanus

functions-framework-api/src/main/java/com/google/cloud/functions/BackgroundFunction.java

@@ -55,5 +55,5 @@ public interface BackgroundFunction<T> {
    * @param context the context of the event. This is a set of values that every event has,
    *     separately from the payload, such as timestamp and event type.
    */
-  void accept(T payload, Context context);
+  void accept(T payload, Context context) throws Exception;
 }

functions-framework-api/src/main/java/com/google/cloud/functions/RawBackgroundFunction.java

@@ -70,5 +70,5 @@ public interface RawBackgroundFunction {
    * @param context the context of the event. This is a set of values that every event has,
    *     separately from the payload, such as timestamp and event type.
    */
-  void accept(String json, Context context);
+  void accept(String json, Context context) throws Exception;
 }