Added a makefile for building and testing.

[amirmghaemi]

This is a small change, but we can use the makefile for authentication and/or starting the log generating bots in the future as well. Also added the make build and make test commands to the README.

[EandrewJones]

I know this is ready to merge, but I'm a strong NO on adding a makefile unless it's solving a problem that cannot be handled by the standard javascript tooling (npm, yarn, npx, ...). In our case, it is not.