App rewritten to fully use express.js and decoupled

App rewritten to fully use express.js for all features related to http. Using routing, body parser for json and other middleware capabilities. `tester.js` also serves a html page that generates violation logs.

Merging https://github.com/mozilla/csp-logger/pull/2 probably not needed anymore. (except bringing in  "Adding GET for /csp to return table as JSON", but I'll do that soon enough)

I added a prototype logger storage and set it to default so that when newly installed, csp-logger doesn't require a running mysql database. 

PS.
I will further develop the logger and other storage options.