weatherforecast rainfall rounding

[vincep5]

Please send your pull requests the develop branch.
Don't forget to add the change to CHANGELOG.md.

Note: Sometimes the development moves very fast. It is highly
recommended that you update your branch of develop before creating a
pull request to send us your changes. This makes everyone's lives
easier (including yours) and helps us out on the development team.
Thanks!

• Does the pull request solve a related issue?
• If so, can you reference the issue?
• What does the pull request accomplish? Use a list if needed.
• If it includes major visual changes please add screenshots.