Replace keycloak-connect protect method with jsonwebtoken.verify

We can use the verify() method that comes with the jsonwebtoken library
to verify the client's auth token is valid.
An invalid token will now return a Problem instance
Updated API spec

app/app.js

@@ -7,7 +7,6 @@ const helmet = require('helmet');
 const moment = require('moment');
 
 const { name: appName, version: appVersion } = require('./package.json');
-const keycloak = require('./src/components/keycloak');
 const log = require('./src/components/log')(module.filename);
 const httpLogger = require('./src/components/log').httpLogger;
 const { getGitRevision } = require('./src/components/utils');
@@ -69,9 +68,6 @@ if (process.env.NODE_ENV !== 'test') {
   app.use(httpLogger);
 }
 
-// Use Keycloak OIDC Middleware
-app.use(keycloak.middleware());
-
 // Block requests until service is ready and mounted
 app.use((_req, res, next) => {
   if (state.shutdown) {