update test expectations in py35/py36 tests

`/usr/bin/env python` is no longer the kernel python

tests/conda/py35-binder-dir/verify

@@ -1,17 +1,28 @@
 #!/usr/bin/env python
+import os
 import sys
-from subprocess import check_output
+from subprocess import STDOUT, check_output
 
-assert sys.version_info[:2] == (3, 5), sys.version
+assert sys.version_info[:2] == (3, 7), sys.version
 
-out = check_output(["micromamba", "--version"]).decode("utf8").strip()
+
+def sh(cmd, **kwargs):
+    return check_output(cmd, **kwargs).decode("utf8").strip()
+
+
+kernel_python = os.path.join(os.environ["KERNEL_PYTHON_PREFIX"], "bin", "python")
+out = sh([kernel_python, "--version"], stderr=STDOUT)
+v = out.split()[1]
+assert v[:3] == "3.5", out
+
+out = sh(["micromamba", "--version"])
 assert out == "1.1.0", out
 
-out = check_output(["mamba", "--version"]).decode("utf8").strip()
+out = sh(["mamba", "--version"])
 assert (
     out
     == """mamba 1.1.0
 conda 4.13.0"""
 ), out
 
-import numpy
+sh([kernel_python, "-c", "import numpy"])

tests/external/reproductions.repos.yaml

@@ -33,7 +33,7 @@
 # Zenodo record of https://github.com/binder-examples/requirements
 - name: 10.5281/zenodo.3242074
   url: 10.5281/zenodo.3242074
-  verify: python -c 'import matplotlib'
+  verify: /srv/conda/envs/kernel/bin/python -c 'import matplotlib'
 # Test that files in git-lfs are properly cloned
 - name: LFS
   url: https://github.com/binderhub-ci-repos/lfs

tests/pipfile/py36/verify

@@ -1,8 +1,8 @@
-#!/usr/bin/env python
+#!/srv/conda/envs/kernel/bin/python
 import sys
 
-import pypi_pkg_test
-import there
-
 print(sys.version_info)
 assert sys.version_info[:2] == (3, 6)
+
+import pypi_pkg_test  # noqa
+import there  # noqa

tests/venv/py35/verify

@@ -1,4 +1,4 @@
-#!/usr/bin/env python3
+#!/srv/conda/envs/kernel/bin/python
 import sys
 
 print(sys.version_info)