missing dependency

Nobody has claimed this yet.

hi @rgerkin

I'm trying to setup my dev env on my computer.

I get this error when I try to install neuronunit

```
(venv) zoran@zoran-XPS-15-9560:/opt/projects/metacell/scidash/scidash$ pip install git+git://github.com/scidash/neuronunit@metacell#egg=neuronunit
Collecting neuronunit
Cloning git://github.com/scidash/neuronunit (to revision metacell) to /tmp/pip-install-kxue2wgg/neuronunit
Running command git clone -q git://github.com/scidash/neuronunit /tmp/pip-install-kxue2wgg/neuronunit
Running command git checkout -b metacell --track origin/metacell
Switched to a new branch 'metacell'
Branch 'metacell' set up to track remote branch 'metacell' from 'origin'.
Running command git submodule update --init --recursive -q
Collecting allensdk==0.14.5
Using cached allensdk-0.14.5.tar.gz (494 kB)
Collecting bluepyopt@ git+https://github.com/russelljjarvis/BluePyOpt@scidash#egg=bluepyopt-9999
Cloning https://github.com/russelljjarvis/BluePyOpt (to revision scidash) to /tmp/pip-install-kxue2wgg/bluepyopt
Running command git clone -q https://github.com/russelljjarvis/BluePyOpt /tmp/pip-install-kxue2wgg/bluepyopt
WARNING: Did not find branch or tag 'scidash', assuming revision or ref.
Running command git checkout -q scidash
error: pathspec 'scidash' did not match any file(s) known to git
ERROR: Command errored out with exit status 1: git checkout -q scidash Check the logs for full command output.
```
I've checked the repo https://github.com/russelljjarvis/BluePyOptBU and it seems that there is no `scidash` branch/tag there

Start by rerunning the pip install command and inspect the dependency metadata that requests BluePyOpt from the missing `scidash` branch. Confirm which available BluePyOpt revision should be used, then verify that a clean virtual environment can install neuronunit without the checkout error.

Written by the indexing model from the issue text.