Added note on Pyinstaller to readme

README.md

@@ -1,3 +1,13 @@
 # arduino-timetable
 
 Module to send commands to an Arduino based on a time table.
+
+
+### Regarding Pyinstaller
+
+As of September 2017 the Pyinstaller version on PyPi is not ready for
+Python 3.6, the developementversion is needed:
+
+~~~
+pip install https://github.com/pyinstaller/pyinstaller/tarball/develop
+~~~