Bump version date for 1.13.6

JorjMcKie · web-flow · commit b46008a33f93 · 2018-05-27T10:38:43.000-04:00
diff --git a/README.md b/README.md
@@ -2,7 +2,7 @@
 
 ![logo](https://github.com/rk700/PyMuPDF/blob/master/demo/pymupdf.jpg)
 
-Release date: May 23, 2018
+Release date: May 27, 2018
 
 # Authors
 * [Ruikai Liu](mailto:lrk700@gmail.com)
