Subpixel edge (#493)

* affine centered on the ROI

* Updates for comments

* remove missed phase args in func signature

* Updates for passing tests

* Updates with tests

* Update for comments.

* Updates for additional comments.

* comments addressed

* Adds an edge check for the correlation template.

* Adds edge check to subpixel_template

* Updates ROI to identify when null pixels exist

* Updates gitignore to skip DS_Store entries

* Updates test fixture for ROI tests

* Updates subpixel to use the new ROI capabilities

* Fixes edge check for all edges

* removes extra comment

* Reverts pg ports to be corret for remote CI

* Update subpixel.py