Completely strip out 3.7 and pypy3 from CI.

Author: ionelmc

ci/test.sh

@@ -31,5 +31,10 @@ bumpversion minor
 bumpversion major
 safe_sed 's/sphinx-build -b linkcheck/#/' tox.ini
 safe_sed 's/,py37,/,/' tox.ini
+safe_sed 's/py37,//' tox.ini
+safe_sed 's/py37-cover,//' tox.ini
+safe_sed 's/py37-nocov,//' tox.ini
 safe_sed 's/,pypy3}/}/' tox.ini
-tox
+safe_sed 's/pypy3-cover,//' tox.ini
+safe_sed 's/pypy3-nocov,//' tox.ini
+tox -l