Bitrise Flutter step inputs

step.yml

inputs:
  - version: 0.3.1-beta
    opts:
      title: "Flutter version"
      summary: Flutter version including channel. Without `v` prefix. E.g. `0.2.8-alpha` or `0.3.0-dev`.
      is_expand: true
      is_required: true

  - working_dir: $BITRISE_SOURCE_DIR
    opts:
      title: "Root directory of Flutter project"
      summary: The root directory of your Flutter project, where your `pubspec.yaml` file is located.
      is_expand: true
      is_required: true

  - commands: build
    opts:
      title: "Flutter commands to be executed"
      summary: |
        `|` separated Flutter commands to be executed in order. E.g. `build`, `test` or `install`.
      is_expand: true
      is_required: true