Redshift Updates

- Implement create_cluster_snapshot endpoint
- Implement describe_cluster_snapshots endpoint
- Implement delete_cluster_snapshot endpoint
- Implement restore_from_cluster_snapshot endpoint
- Implement limited support for describe_tags endpoint
- Correctly serialize errors to json (for boto) or xml (for boto3)
- Simulate cluster spin up by returning initial status as 'creating' and subsequent statuses as 'available'
- Fix issue with modify_cluster endpoint where cluster values get set to None when omitted from request
- Add 'Endpoint' key to describe_clusters response syntax

moto/redshift/exceptions.py

@@ -56,3 +56,18 @@ class InvalidSubnetError(RedshiftClientError):
         super(InvalidSubnetError, self).__init__(
             'InvalidSubnet',
             "Subnet {0} not found.".format(subnet_identifier))
+
+
+class ClusterSnapshotNotFoundError(RedshiftClientError):
+    def __init__(self, snapshot_identifier):
+        super(ClusterSnapshotNotFoundError, self).__init__(
+            'ClusterSnapshotNotFound',
+            "Snapshot {0} not found.".format(snapshot_identifier))
+
+
+class ClusterSnapshotAlreadyExistsError(RedshiftClientError):
+    def __init__(self, snapshot_identifier):
+        super(ClusterSnapshotAlreadyExistsError, self).__init__(
+            'ClusterSnapshotAlreadyExists',
+            "Cannot create the snapshot because a snapshot with the "
+            "identifier {0} already exists".format(snapshot_identifier))