Support for Firefox

Added

• Support for Firefox

Activate via button

Changed

• The extension is now loaded by clicking the extension button, not by inspecting the URL pattern.
  This is safer, and allows the user to choose when to load the extension and when not to.

Background for errored pipelines

Added

• Background image display for pipelines in an errored state.
• Icons in PNG and AI format, thanks to Cynthia Conklin!

Bump version in manifest

Changed

• Bumped manifest version.

Options and legacy Concourse support

Added

• Customization of image backgrounds via Options.
• Support for Concourse v4.
• Styling of legend to make it more visible.

Removed

• Loading the extension on pages for individual jobs/builds.

Initial release

Added

• Hard-coded image backgrounds.