fix bootstrap.py with proxy

[pirovc]

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• I have read the guidelines for bioconda recipes.
• This PR adds a new recipe.
• AFAIK, this recipe is directly relevant to the biological sciences (otherwise, please submit to the more general purpose conda-forge channel).
• This PR updates an existing recipe.
• This PR does something else (explain below).

Under a machine with a proxy configured the script bootstrap.py was failing with the following error:

$ ./bootstrap.py /tmp/miniconda
fatal: unable to access 'https://github.com/bioconda/bioconda-recipes.git/': Failed to connect to github.com port 443: Connection refused
Traceback (most recent call last):
  File "bootstrap.py", line 110, in <module>
    sp.check_call(['.circleci/setup.sh'], env=env)
  File "/usr/lib/python3.5/subprocess.py", line 271, in check_call
    raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '['.circleci/setup.sh']' returned non-zero exit status 128

This PR should fix it by passing the https_proxy variable to the .circleci/setup.sh call.

@bioconda/core please check

[epruesse]

Does this fix the problem for you? Does the whole thing work?
I've messed with some of the docker stuff recently, and there was https_proxy specific code in there. If you could try whether bioconda build --docker (and --mulled) work, that would be very much appreciated.

[biocondabot]

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