Map code coverage to typescript source files

[chancehudson]

The current build system takes all typescript files and compiles them into a single javascript file that exports an express server. This single javascript file is tested using a suite of javascript files in /test. The server is loaded into memory and run against a mongodb instance run in an ephemeral docker container.

The results of that are then converted into coverage reports like this that make source analysis easy. Source maps need to be used to map the exported coverage to the new typescript source files.

Tests can still be developed using npm run coverage as the bug is simply in how webpack transcodes the title file structure I think.