Handle permission errors during bucket creation

This commit requires jclouds 2.1.0.  References #122.

src/main/java/org/gaul/s3proxy/S3Exception.java

@@ -42,6 +42,10 @@ public final class S3Exception extends Exception {
                 ImmutableMap.<String, String>of());
     }
 
+    S3Exception(S3ErrorCode error, String message, Throwable cause) {
+        this(error, message, cause, ImmutableMap.<String, String>of());
+    }
+
     S3Exception(S3ErrorCode error, String message, Throwable cause,
                 Map<String, String> elements) {
         super(requireNonNull(message), cause);

src/main/java/org/gaul/s3proxy/S3ProxyHandler.java

@@ -28,6 +28,7 @@ import java.io.PushbackInputStream;
 import java.io.Writer;
 import java.net.URLDecoder;
 import java.nio.charset.StandardCharsets;
+import java.nio.file.AccessDeniedException;
 import java.security.InvalidKeyException;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
@@ -1231,6 +1232,10 @@ public class S3ProxyHandler {
             created = blobStore.createContainerInLocation(location,
                     containerName, options);
         } catch (AuthorizationException ae) {
+            if (ae.getCause() instanceof AccessDeniedException) {
+                throw new S3Exception(S3ErrorCode.ACCESS_DENIED,
+                        "Could not create bucket", ae);
+            }
             throw new S3Exception(S3ErrorCode.BUCKET_ALREADY_EXISTS, ae);
         }
         if (!created) {