Unbreak Travis CI
There is a transitive dependency on the wheel package through
psutil, but it is specified in pyproject.toml there, and
`pip download` DOES NOT pick it up, but fails on `pip install`.
@@ -4,6 +4,10 @@ set -e -x
pip install --quiet -U setuptools wheel pip
pip download --dest=/tmp/deps .[test,docs]
+# There is a transitive dependency on wheel through psutil,
+# but it is specified in pyproject.toml, and `pip download`
+# DOES NOT pick it up, but fails on `pip install` nonetheless.
+pip download --dest=/tmp/deps wheel
pip install -U --no-index --find-links=/tmp/deps /tmp/deps/*
git clone https://github.com/edgedb/edgedb-python.git edgedb
