Feat: implement per operator settings cache

Fix: fix linter-found issues

Chore: move findOperatorId to own middleware file

Chore: delete old routes.js file and rename new-routes.js to routes.js

Fix: PR fixes

lib/middlewares/operatorId.js

@@ -0,0 +1,30 @@
+const pify = require('pify')
+const fs = pify(require('fs'))
+const hkdf = require('futoin-hkdf')
+
+const state = require('./state')
+const mnemonicHelpers = require('../mnemonic-helpers')
+const options = require('../options')
+
+function computeOperatorId (masterSeed) {
+  return hkdf(masterSeed, 16, { salt: 'lamassu-server-salt', info: 'operator-id' }).toString('hex')
+}
+
+function getMnemonic () {
+  if (state.mnemonic) return Promise.resolve(state.mnemonic)
+  return fs.readFile(options.mnemonicPath, 'utf8').then(mnemonic => {
+    state.mnemonic = mnemonic
+    return mnemonic
+  })
+}
+
+function findOperatorId (req, res, next) {
+  getMnemonic().then(mnemonic => {
+    return computeOperatorId(mnemonicHelpers.toEntropyBuffer(mnemonic))
+  }).then(id => {
+    res.locals.operatorId = id
+  }).catch(e => console.error('Error while computing operator id\n' + e))
+  next()
+}
+
+module.exports = findOperatorId