Use tox configuration for documentation link check

Author: nezhar

.travis.yml

@@ -24,6 +24,7 @@ matrix:
       - { python: "3.7", env: TOXENV=base }
       - { python: "3.7", env: TOXENV=lint }
       - { python: "3.7", env: TOXENV=docs }
+      - { python: "3.7", env: TOXENV=docs-links }
 
       - python: "3.7"
         env: TOXENV=dist
@@ -33,18 +34,9 @@ matrix:
           - tox --installpkg ./dist/djangorestframework-*.whl
           - tox  # test sdist
 
-      - python: "3.7"
-        env: DOCS=links
-        script:
-          - pip install -r requirements/requirements-documentation.txt
-          - mkdocs serve &
-          - WAIT_TIME=0 && until nc -vzw 2 localhost 8000 || [ $WAIT_TIME -eq 5 ]; do sleep $(( WAIT_TIME++ )); done
-          - if [ $WAIT_TIME == 5 ]; then echo cannot start mkdocs server on http://localhost:8000; exit 1; fi
-          - pylinkvalidate.py -P http://localhost:8000/
-
     allow_failures:
       - env: DJANGO=master
-      - env: DOCS=links 
+      - env: TOXENV=docs-links 
 
 install:
     - pip install tox tox-venv tox-travis

tox.ini

@@ -57,3 +57,16 @@ commands = mkdocs build
 deps =
        -rrequirements/requirements-testing.txt
        -rrequirements/requirements-documentation.txt
+
+
+[testenv:docs-links]
+basepython = python3.7
+skip_install = true
+commands = 
+        mkdocs serve \&
+        WAIT_TIME = 0
+        until nc -vzw 2 localhost 8000 || [ $WAIT_TIME -eq 5 ]; do sleep $(( WAIT_TIME++ )); done
+        if [ $WAIT_TIME -eq 5 ]; then echo cannot start mkdocs server on http://localhost:8000; exit 1; fi
+        pylinkvalidate.py -P http://localhost:8000/
+deps =
+       -rrequirements/requirements-documentation.txt