Avoid circular dependency if when installing

slurm_gcp_docker now requires that wolF be installed in the image, in order
to execute wolF scripts on worker nodes. This prevents Canine from trying
to install slurm_gcp_docker if it detects that it's being built in the
slurm_gcp_docker container.

setup.py

@@ -57,9 +57,9 @@
         'tables>=3.6.1',
         'google-crc32c>=1.5.0',
         'google-cloud-compute>=1.6.1',
-        #'slurm_gcp_docker>=0.12',
-        'slurm_gcp_docker @ git+https://github.com/getzlab/[email protected]',
-    ],
+    ] + (['slurm_gcp_docker @ git+https://github.com/getzlab/slurm_gcp_docker@v0.16.0']
+          if not os.path.exists("/.dockerenv") else []
+        ), # avoid circular dependency of slurm_gcp_docker -> wolf -> canine,
     python_requires = ">3.7",
     classifiers = [
         "Development Status :: 4 - Beta",