Merge branch 'remove_pipenv' into 'master'

Removed pipenv

See merge request lscsoft/bilby!724

Pipfile

-[[source]]
-url = "https://pypi.org/simple"
-verify_ssl = true
-name = "pypi"
-
-[packages]
-future = "*"
-corner = "*"
-numpy = "==1.15.2"
-ligotimegps = "<=1.2.3"
-matplotlib = "<3"
-scipy = ">=0.16"
-pandas = "==0.23.0"
-deepdish = "==0.3.6"
-mock = "*"
-astropy = "<3"
-gwpy = "*"
-theano = "*"
-lalsuite = "*"
-dill = "*"
-
-# cpnest = "*"
-dynesty = "*"
-emcee = "*"
-nestle = "*"
-ptemcee = "*"
-pymc3 = "*"
-
-[requires]
-
-[dev-packages]
-
-[pipenv]
-allow_prereleases = false