Create module for request throttling

[benlowry]

Help is wanted on this and I am available to assist anyone working on this problem. Join the freenode IRC #dashboard chatroom for support. Web IRC client

Dashboard needs to support request throttling to prevent brute force attacks on signing in. This should be integrated with Dashboard directly and have an ENV variable that will specify the limit.

If it is not a lot of code it could be added to /src/server.js directly, otherwise a before server request handler can examine requests efficiently too that would require a /src/server/script.js and including it in package.json configuration.

There is an express.js module that will probably be a good source for this.