Revert "Merge pull request #812 from chebee7i/pydot". Addresses #812.

This reverts commit e736d4b4db44f45c59039d44f92013748cbef3f4, reversing
changes made to ceb31d0f4f14556d4e804868efd23c11f2e6b776.
Merge pull request #950 from chebee7i/revert_812

Revert "Merge pull request #812 from chebee7i/pydot". Addresses #812.