v0.2.0 - Google sign-in support with OAuth2

This version adds support for Google sign-in allowing you to sign in with your Google user. If your user is also registered in the database you'll have access to a secret. If the user has the right access level it will have access to more than one secret.

• Database: Added email, access level and image links to the "heroes" table.
• Frontend: Added Google sign-in button and sign-in functionality that adds an authorization header to the subsequent API call.
• Backend: added OAuth2 authentication, validating the token passed in with the authentication header. If the user is registered, a secret will be added to the result. If the user also has access level >= 100, another secret will be added.
• Fixed the hack where images were added in the front-end only. The image paths are now in the database as they should. Note however that if you sign in with your Google user, the profile picture, name and email used there will also be used in the app.

NOTE: you need to generate and add your own Google client ID for Google sign-in to work. See the new section in README.md for instructions

v0.1.0 - Hello World

A first working version