Merge pull request #4522 from Gallaecio/travis-tox-py

Remove TOXENV from .travis.yml unless needed

.travis.yml

@@ -15,17 +15,14 @@ matrix:
       python: 3.7  # Keep in sync with .readthedocs.yml
 
     - env: TOXENV=pypy3
-    - env: TOXENV=py35
-      python: 3.5
+    - python: 3.5
     - env: TOXENV=pinned
       python: 3.5
     - env: TOXENV=asyncio
       python: 3.5.2
-    - env: TOXENV=py36
-      python: 3.6
-    - env: TOXENV=py37
-      python: 3.7
-    - env: TOXENV=py38
+    - python: 3.6
+    - python: 3.7
+    - env: PYPI_RELEASE_JOB=true
       python: 3.8
     - env: TOXENV=extra-deps
       python: 3.8
@@ -63,4 +60,4 @@ deploy:
   on:
     tags: true
     repo: scrapy/scrapy
-    condition: "$TOXENV == py37 && $TRAVIS_TAG =~ ^[0-9]+[.][0-9]+[.][0-9]+(rc[0-9]+|[.]dev[0-9]+)?$"
+    condition: "$PYPI_RELEASE_JOB == true && $TRAVIS_TAG =~ ^[0-9]+[.][0-9]+[.][0-9]+(rc[0-9]+|[.]dev[0-9]+)?$"