Add test for docker build

.github/workflows/run-tests.yml

@@ -14,7 +14,7 @@ on:
 
 jobs:
 
-  tests:
+  tests_python:
     runs-on: ubuntu-latest
     strategy:
       matrix:
@@ -35,7 +35,7 @@ jobs:
 
     - name: Check code style with flake8 (lint)
       run: |
-        # warnings if there are Python syntax errors or undefined names 
+        # warnings if there are Python syntax errors or undefined names
         # (remove --exit-zero to fail when syntax error)
         flake8 . --count --exit-zero --select=E9,F63,F7,F82 --show-source --statistics
         # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
@@ -44,3 +44,12 @@ jobs:
     - name: Test with pytest
       run: pytest -v
 
+
+  test_docker_build:
+    needs: [ tests_python ]
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Docker build
+          run: docker build -t libretranslate .