400 instead of 500 when params validation failed

[c910335]

Description

ValidationFailed is apparently a client error due to passing invalid params.
Thus, server should response 400 Bad Request instead of 500 Internal Server Error when ValidationFailed is raised.

Steps to Reproduce

1. Start a new amber project
2. Generate a scaffold with at least one field
3. POST it without params

Expected behavior: 400 Bad Request

Actual behavior: 500 Internal Server Error

Reproduces how often: always

Versions

v0.7.2 and master

Additional Information

I think @faustinoaq is ready to fix this.

[faustinoaq]

@c910335 Thank you for helping me to open issues, very appreciated! 👍 🎉

[faustinoaq]

Fixed by #864

[faustinoaq]

#864 is not merged yet, still work in progress 😅

[drujensen]

This is now fixed. The exceptions page shows and its a 500 error.