V2.0.0 - Dependency support

[2.0.0] - 2020-07-13

Changed

• updated dependencies
• moved the build script to a new build/ directory
• updated build script to transpile with babel
• updated build script to exclude package-lock.json
• refactored source code to use classes
• stopped assuming /status is the route name in the clients, this has to be specified in the service's options now.
• updated the README.md
• updated linting

Added

• support for route dependencies in the options
• named import: "heartbeatMiddlewareClient" for clients
• added demo setup