bump patch version to incorporate #20

Author: j-fu

Project.toml

@@ -1,7 +1,7 @@
 name = "ExtendableSparse"
 uuid = "95c220a8-a1cf-11e9-0c77-dbfce5f500b3"
 authors = ["Juergen Fuhrmann <juergen.fuhrmann@wias-berlin.de>"]
-version = "0.9.0"
+version = "0.9.1"
 
 [deps]
 DocStringExtensions = "ffbed154-4ef7-542d-bbb7-c09d3a79fcae"