Fix Circle CI config

Author: kazk

.circleci/config.yml

@@ -1,16 +1,16 @@
 version: 2
 jobs:
-  test:
+  build:
     docker:
-      - image: ubuntu:18.04
+      - image: circleci/python:3.7-buster
     working_directory: ~/repo
     steps:
       - checkout
       - run:
           name: Install Dependencies
           command: |
             sudo apt-get update
-            sudo apt-get install -y --no-install-recommends gforth python
+            sudo apt-get install -y --no-install-recommends gforth
       - run:
           name: Run Tests
           command: python test/run-tests.py -v