Update Dependencies

[mjhenkes]

Description of Issue

Several dependencies are out of date and have potential security vulnerabilities.

I took a brief look. It appeared most would be resolved by upgrading webpack-dev-server, webpack, and mocha versions.

[mjhenkes]

Just checking in. We're up to 21 security warnings.

[mhemesath]

I started working on this, currently working through non-passive chai/sinon changes.