Es6/es7 rgomex structure

[rubengomex]

• Add Readme file that closes #1

• Add Unit and integration testing that closes #3

• Add configuration module to be able to see properties from config.json or .env file. This closes #10

• Set Eslint enable

• Add also js documentation and generation

• Add also API documentation and generation.

• Add dependencies to the package.json

• Add code coverage

• Add gitignore

• Add License MIT

• All the structure are in es6/es7 node js features (classes, promises, async await keywords.

• Missing some refactor in authorization routes.