Add failure scenarios tests for connection, appendToStream, deleteStream (wip)

src/errors/streamDeletedError.js

@@ -0,0 +1,11 @@
+var util = require('util');
+
+function StreamDeletedError(stream) {
+  Error.captureStackTrace(this, this.constructor);
+  this.name = this.constructor.name;
+  this.message = util.format("Event stream '%s' is deleted.", stream);
+  this.stream = stream;
+}
+util.inherits(StreamDeletedError, Error);
+
+module.exports = StreamDeletedError;