Active storage: Image variant options not correct in docs

[lucfranken]

Steps to reproduce

Using Rails 5.2.0

When following this example:

http://api.rubyonrails.org/classes/ActiveStorage/Variant.html

avatar.variant(resize: "100x100", monochrome: true, flip: "-90")

Expected behavior

Image should be rendered as rotated.

Actual behavior

I get an error:

failed with error: gm mogrify: Unrecognized option (-90).

Fix:

According to: https://github.com/minimagick/minimagick the option should be called rotate:

avatar.variant(resize: "100x100", monochrome: true, rotate: "-90")

So flip changed to rotate.

System configuration

Rails version: 5.2.0

Ruby version: ruby 2.5.1p57 (2018-03-29 revision 63029) [x86_64-darwin17]

[ci skip]

[rails-bot]

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[kamipo]

Thanks!