linuxbrew: use pipenv 2018.10.13 (virtualenv 16.0.0)
linuxbrew: use pipenv 2018.10.13 (virtualenv 16.0.0)

See https://github.com/pypa/pipenv/issues/3395
See https://github.com/pypa/virtualenv/issues/1270

tobiipro/support-firecloud,tobiipro/support-firecloud,tobiipro/support-firecloud,tobiipro/support-firecloud