Replace signale with pino for logging (#349)

* Replace signale with pino

* Increase config flexibility

* Add nodemon to dev dependencies

Author: cbovis

.env.example

@@ -1,2 +1,4 @@
 CONNECTION_STRING=mongodb://localhost:27017/zrx-tracker
+ELASTIC_SEARCH_URL=http://localhost:9200
 NODE_ENV=development
+PINO_ELASTIC_SEARCH_URL=

.env.prod.example

@@ -1,2 +1,4 @@
 BUGSNAG_TOKEN=
 CONNECTION_STRING=
+ELASTIC_SEARCH_URL=
+PINO_ELASTIC_SEARCH_URL=

config/jest/setup.js

@@ -8,7 +8,6 @@ module.exports = {
     '!*.config.js',
     '!config/**',
   ],
-  setupFiles: ['<rootDir>/config/jest/setup'],
   testEnvironment: 'node',
   testMatch: ['**/__tests__/**/*.js', '**/*.test.js'],
 };