Make interfaces with only statics into classes

This prevents instantiation.  Found via error-prone 2.3.3.
diff --git a/apis/rackspace-clouddns/src/main/java/org/jclouds/rackspace/clouddns/v1/CloudDNSExceptions.java b/apis/rackspace-clouddns/src/main/java/org/jclouds/rackspace/clouddns/v1/CloudDNSExceptions.java
index bd63173..a699b2b 100644
--- a/apis/rackspace-clouddns/src/main/java/org/jclouds/rackspace/clouddns/v1/CloudDNSExceptions.java
+++ b/apis/rackspace-clouddns/src/main/java/org/jclouds/rackspace/clouddns/v1/CloudDNSExceptions.java
@@ -23,7 +23,11 @@
 /**
  * Exceptions likely to be encountered when using {@link CloudDNSApi}
  */
-public interface CloudDNSExceptions {
+public final class CloudDNSExceptions {
+   private CloudDNSExceptions() {
+      throw new AssertionError("intentionally not implemented");
+   }
+
    /**
     * A Job errored out.
     */
diff --git a/providers/dynect/src/main/java/org/jclouds/dynect/v3/DynECTExceptions.java b/providers/dynect/src/main/java/org/jclouds/dynect/v3/DynECTExceptions.java
index 735b252..b681789 100644
--- a/providers/dynect/src/main/java/org/jclouds/dynect/v3/DynECTExceptions.java
+++ b/providers/dynect/src/main/java/org/jclouds/dynect/v3/DynECTExceptions.java
@@ -19,7 +19,11 @@
 /**
  * Exceptions likely to be encountered when using {@link DynECTApi}
  */
-public interface DynECTExceptions {
+public final class DynECTExceptions {
+   private DynECTExceptions() {
+      throw new AssertionError("intentionally not implemented");
+   }
+
    /**
     * You must wait until another job is finished before attempting this command
     * again
diff --git a/providers/ultradns-ws/src/main/java/org/jclouds/ultradns/ws/UltraDNSWSExceptions.java b/providers/ultradns-ws/src/main/java/org/jclouds/ultradns/ws/UltraDNSWSExceptions.java
index 0122ddf..2f107af 100644
--- a/providers/ultradns-ws/src/main/java/org/jclouds/ultradns/ws/UltraDNSWSExceptions.java
+++ b/providers/ultradns-ws/src/main/java/org/jclouds/ultradns/ws/UltraDNSWSExceptions.java
@@ -19,7 +19,10 @@
 /**
  * Exceptions likely to be encountered when using {@link UltraDNSWSApi}
  */
-public interface UltraDNSWSExceptions {
+public final class UltraDNSWSExceptions {
+   private UltraDNSWSExceptions() {
+      throw new AssertionError("intentionally not implemented");
+   }
 
    /**
     * The Zone or other resource already exists