Add Python 3.8 to docker-compose-based tests

Author: Dobiasd

docker-compose.yml

@@ -4,7 +4,7 @@ services:
 
   unit-tests-3-6:
     build:
-      context: test
+      context: .
       dockerfile: test/Dockerfile_3.6
     volumes:
      - .:/undictify
@@ -13,9 +13,18 @@ services:
 
   unit-tests-3-7:
     build:
-      context: test
+      context: .
       dockerfile: test/Dockerfile_3.7
     volumes:
      - .:/undictify
     working_dir: /undictify
     entrypoint: ./test/install_from_local_and_run_code_checks_3_7_and_up.sh
+
+  unit-tests-3-8:
+    build:
+      context: .
+      dockerfile: test/Dockerfile_3.8
+    volumes:
+     - .:/undictify
+    working_dir: /undictify
+    entrypoint: ./test/install_from_local_and_run_code_checks_3_7_and_up.sh

test/Dockerfile_3.8

@@ -0,0 +1,4 @@
+FROM python:3.8
+
+RUN pip3 install --upgrade pip
+RUN pip3 install pylint mypy

test/install_from_local.sh

@@ -1,4 +1,5 @@
 #!/usr/bin/env bash
 set -e
 
+pip3 install --upgrade pip
 pip3 install .