Add react-dropdown dependency
This provides a styleable custom drop-down/select-box implementation
that may be used in-place of the native select element.  It provides the
ability to have rich HTML elements as the options.
"prop-types": "^15.7.2",
"react": "^16.13.1",
"react-dom": "^16.13.1",
+ "react-dropdown": "^1.7.0",
"react-router-dom": "^5.1.2",
"react-toast-notifications": "^2.4.0",
"splinter-saplingjs": "github:cargill/splinter-saplingjs#master",
