Correct mock method visibility for newer JRuby tests

Only affects appraisals/rails tests right now it seems where the MockHttpSession is used.

Author: chadlwilson

src/spec/java/org/jruby/rack/mock/MockHttpSession.java

@@ -101,7 +101,7 @@ public String getId() {
 		return this.id;
 	}
 
-    void setId(String id) {
+    public void setId(String id) {
         this.id = id;
     }
 
@@ -256,7 +256,7 @@ public String toString() {
         return getClass().getName() + "@" + Integer.toHexString(hashCode()) + this.attributes;
     }
 
-    Map<String, Object> getAttributes() {
+    public Map<String, Object> getAttributes() {
         return attributes;
     }