Add basic config file handling methods.
Add server test scripts.
Load environment specific configuration file in server.
Throw error if no environment is set.
Add mongo connection module.
Add test environment configuration file.
Add db configuration for development environment.
Move mongo initialisation out of the express initialisation.
Don't use path.join for creating the config path.

As join normalizes the path and thereby strips leading ./ the result
can't always be used as a parameter for require.
Use port from configuration file.
Read database configuration from config.
Add supertest as development dependency.
Reuse db connection if already present.
Add additional checks for valid db configurations.
Update README.md
Update README.md
Call the mongo connect method with the current configuration.
Check provided config after possible return of already existing db.
Add first minimalistic post endpoint for registering users.
Merge pull request #4 from lxanders/create-users-post-endpoint

Create users post endpoint