Change readme to contain 3.7 link

README.rst

@@ -15,7 +15,7 @@ To get a feeling of QCoDeS read
 and/or browse the Jupyter notebooks in `docs/examples
 <https://github.com/QCoDeS/Qcodes/tree/master/docs/examples>`__ .
 
-QCoDeS is compatible with Python 3.6+. It is primarily intended for use
+QCoDeS is compatible with Python 3.7+. It is primarily intended for use
 from Jupyter notebooks, but can be used from traditional terminal-based
 shells and in stand-alone scripts as well. The features in
 `qcodes.utils.magic` are exclusively for Jupyter notebooks.