Docker Build Failing on Git

[iguy0]

When attempting to install on my Ubuntu 18.04 machine i receive the following error:

Collecting git+https://github.com/alpacahq/zipline@98e860b55c9fc4a8a825fe6c0f558b0fb2866bf8
  Cloning https://github.com/alpacahq/zipline (to revision 98e860b55c9fc4a8a825fe6c0f558b0fb2866bf8) to /tmp/pip-req-build-dptyknir
fatal: reference is not a tree: 98e860b55c9fc4a8a825fe6c0f558b0fb2866bf8
Command "git checkout -q 98e860b55c9fc4a8a825fe6c0f558b0fb2866bf8" failed with error code 128 in /tmp/pip-req-build-dptyknir
The command '/bin/sh -c pip install git+https://github.com/alpacahq/zipline@98e860b55c9fc4a8a825fe6c0f558b0fb2866bf8' returned a non-zero code: 1

Please let me know if additional information is needed.

Thank You