feat(docker): Allow configUrl to be used in Docker

[cmckni3]

• Adds CONFIG_URL to Dockerfile ENV
• Handles swapping url and urls with configUrl if specified

Fixes #4861

Built image locally:

docker build -t swaggerapi/swagger-ui:latest .

Run local image pointing CONFIG_URL to http-server containing swagger-config.json:

docker run -p 8080:8080 -e CONFIG_URL=http://localhost:8000/swagger-config.json swaggerapi/swagger-ui:latest

Open browser to localhost:8080

• No code changes (src/ is unmodified: changes to documentation, CI, metadata, etc.)

• Dependency changes (any modification to dependencies in package.json)

• Bug fixes (non-breaking change which fixes an issue)

• Improvements (misc. changes to existing features)

• Features (non-breaking change which adds functionality)

• are breaking changes to a public API (config options, System API, major UI change, etc).

• are breaking changes to a private API (Redux, component props, utility functions, etc.).

• are breaking changes to a developer API (npm script behavior changes, new dev system dependencies, etc).

• are not breaking changes.

• My changes do not require a change to the project documentation.

• My changes require a change to the project documentation.

• If yes to above: I have updated the documentation accordingly.

• My changes can not or do not need to be tested.

• My changes can and should be tested by unit and/or integration tests.

• If yes to above: I have added tests to cover my changes.

• If yes to above: I have taken care to cover edge cases in my tests.

• All new and existing tests passed.

[cmckni3]

Build failure says cypress binary is missing

[shockey]

@cmckni3: Build failure says cypress binary is missing

Don't worry about Travis, Jenkins is the source of truth 😄