gammapy 0.18.2 environment has python requirement 3.7.0, breaking jupyter notebook

The gammapy 0.18.2 environment that one should download in the installation instructions has the line

  - python=3.7.0

The current version of 3.7 is 3.7.9 and 3.7.0 had a bug that prevented juputer notebooks from starting, resulting in this error:

❯ jupyter notebook
[I 14:07:18.893 NotebookApp] JupyterLab extension loaded from /home/maxnoe/.local/anaconda/envs/gammapy-0.18.2/lib/python3.7/site-packages/jupyterlab
[I 14:07:18.894 NotebookApp] JupyterLab application directory is /home/maxnoe/.local/anaconda/envs/gammapy-0.18.2/share/jupyter/lab
[I 14:07:18.896 NotebookApp] Serving notebooks from local directory: /home/maxnoe/Projects/gammapy-tutorials
[I 14:07:18.896 NotebookApp] Jupyter Notebook 6.2.0 is running at:
[I 14:07:18.896 NotebookApp] http://localhost:8888/?token=35127264abaa0268cdb104dbea1b0b3f8e918abe4de01a4c
[I 14:07:18.896 NotebookApp]  or http://127.0.0.1:8888/?token=35127264abaa0268cdb104dbea1b0b3f8e918abe4de01a4c
[I 14:07:18.896 NotebookApp] Use Control-C to stop this server and shut down all kernels (twice to skip confirmation).
Traceback (most recent call last):
  File "/home/maxnoe/.local/anaconda/envs/gammapy-0.18.2/bin/jupyter-notebook", line 11, in <module>
    sys.exit(main())
  File "/home/maxnoe/.local/anaconda/envs/gammapy-0.18.2/lib/python3.7/site-packages/jupyter_core/application.py", line 254, in launch_instance
    return super(JupyterApp, cls).launch_instance(argv=argv, **kwargs)
  File "/home/maxnoe/.local/anaconda/envs/gammapy-0.18.2/lib/python3.7/site-packages/traitlets/config/application.py", line 845, in launch_instance
    app.start()
  File "/home/maxnoe/.local/anaconda/envs/gammapy-0.18.2/lib/python3.7/site-packages/notebook/notebookapp.py", line 2269, in start
    self.launch_browser()
  File "/home/maxnoe/.local/anaconda/envs/gammapy-0.18.2/lib/python3.7/site-packages/notebook/notebookapp.py", line 2200, in launch_browser
    browser = webbrowser.get(self.browser or None)
  File "/home/maxnoe/.local/anaconda/envs/gammapy-0.18.2/lib/python3.7/webbrowser.py", line 42, in get
    register_standard_browsers()
  File "/home/maxnoe/.local/anaconda/envs/gammapy-0.18.2/lib/python3.7/webbrowser.py", line 567, in register_standard_browsers
    cmd = _synthesize(cmdline, -1)
  File "/home/maxnoe/.local/anaconda/envs/gammapy-0.18.2/lib/python3.7/webbrowser.py", line 116, in _synthesize
    register(browser, None, controller, update_tryorder)
TypeError: register() takes from 2 to 3 positional arguments but 4 were given

The env file should just remove the bugfix version of the python version (and probably also of many other depedencies):

[maxnoe]

Then it might be a linux specific problem. Anyways, it is not good to fix the bugfix-release version of python for newcomers.

[adonath]

Thanks @Bultako!