vvolkl e575ba2773 bugfix: Update run-time dependencies of py-xenv (#16460) ...

Otherwise, if I run `xenv` after `spack load py-xenv` it fails with:
```
Traceback (most recent call last):
  File "/home/vavolkl/spack/opt/spack/linux-centos7-broadwell/gcc-8.3.0/py-xenv-develop_2018-12-20-lqbxakapsepqo5w3sjhhokj5o7c5jei2/bin/xenv", line 6, in <module>
    from pkg_resources import load_entry_point
ModuleNotFoundError: No module named 'pkg_resources'
```

2020-05-04 19:41:19 -05:00

..

package.py

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