Cosine similarity methods

[corbanvilla]

Added cosine similarity face-recognition methods to api.py along with unit testing.

I did a bunch of facial recognition for a school project and I found that for our use-case, cosine similarity was often more accurate and better at finding matches than euclidean distance so I added a couple methods that implement the formula.

[rememberlenny]

Looks good! Thank you!

[adilsheraz]

Nice

[emmywizzy4jah]

Please what about if a person captured by webcam is putting on a face mask but his/her image in my list is not putting on face mask. Will it recognize it?

[corbanvilla]

@parthematics agreed and fixed!

[corbanvilla]

@emmywizzy4jah there's too many factors to say for sure, it will depend on the quality of both sources, the mask positioning and the model's ability to extract features to name a few... you may or may not see better performance, please feel free to try!