Add snapshot instances admin APIs

Add new API entry points for share snapshot instances:
- share-snapshot-instance-list
- share-snapshot-instance-show
- share-snapshot-instance-reset-status

APIImpact
DocImpact

Implements: blueprint snapshot-instances
Change-Id: Ica1e81012f19926e0f1ba9cd6d8eecc5fbbf40b5
diff --git a/manila_tempest_tests/share_exceptions.py b/manila_tempest_tests/share_exceptions.py
index 3a11531..9b84d02 100644
--- a/manila_tempest_tests/share_exceptions.py
+++ b/manila_tempest_tests/share_exceptions.py
@@ -37,6 +37,11 @@
     message = "Snapshot %(snapshot_id)s failed to build and is in ERROR status"
 
 
+class SnapshotInstanceBuildErrorException(exceptions.TempestException):
+    message = ("Snapshot instance %(id)s failed to build and is in "
+               "ERROR status.")
+
+
 class CGSnapshotBuildErrorException(exceptions.TempestException):
     message = ("CGSnapshot %(cgsnapshot_id)s failed to build and is in ERROR "
                "status")