Add SocketError for IPC errors to use

Change-Id: I38ac433810388b7152c43420908a843816141bfb
diff --git a/errors.py b/errors.py
index 130ead6..6d2e06c 100644
--- a/errors.py
+++ b/errors.py
@@ -37,3 +37,8 @@
     Invalid configuration
     """
 
+class SocketError(VlandError):
+    """
+    Socket connection failure
+    """
+