Downgrade to py36

Dockerfile

@@ -11,9 +11,9 @@
 # set the base image. default is python
 ARG base=python
 # set the tag (e.g. latest, 3.8, 3.7 : for python)
-ARG tag=3.8-slim
+ARG tag=3.6-slim
 
-# Base image, e.g. python:3.8-slim
+# Base image, e.g. python:3.6-slim
 FROM ${base}:${tag}
 
 LABEL maintainer='B.Esteban, T.Kerzenmacher, V.Kozlov (KIT)'

docs/dev_guide/local-install.rst

@@ -4,7 +4,7 @@ Local installation
 To run tests, you need to install the tool in your system without docker.
 
 As first step ensure you have the following dependencies:
- - python_ > 3.8
+ - python_ > 3.6
  - pip_ > 20.0.2
  - gcc_
  - g++_

docs/dev_guide/tests.rst

@@ -19,6 +19,5 @@ To start testing simply run:
 
     $ tox
     ...
-    py37: commands succeeded
-    py38: commands succeeded
+    py36: commands succeeded
 

setup.cfg

@@ -13,7 +13,7 @@ authors_email =
   B.Esteban Sanchis <borja.sanchis@kit.edu>
 classifiers =
     License :: OSI Approved :: GNU General Public License (GPL)
-    Programming Language :: Python :: 3.8
+    Programming Language :: Python :: 3.6
 
 [options]
 packages = find:

tox.ini

@@ -4,7 +4,7 @@
 # and then run "tox" from this directory.
 
 [tox]
-envlist = py38
+envlist = py36
 
 [testenv]
 deps =