C++ Implementation of Jaccard Similiartiy

[JerryXin2]

Me and Garrett were wondering about how we could import the token class and declare it in C++: after we know how to do that, we both feel like we could write the C++ code.

[OlivierBinette]

@JerryXin2 I haven't implemented the Tokenizer class in C++ yet, so we'd have to do that first. You can give it a shot or otherwise I'll work on it this weekend.