## Changes
This PR introduces the `skip_prompt_if` extension to the jsonschema
library. If the inputs provided by the user match the JSON schema then
the prompt for that property is skipped.
Right now only constant checks are supported, but if in the future more
complicated conditionals are required, this can be extended to support
`allOf`, `oneOf`, `anyOf` etc allowing template authors to specify
conditionals of arbitary complexity.
## Tests
Unit tests and manually.