Log Message:
graphics/ruby-RMagick: update to 3.1.0

## RMagick 3.1.0

Deprecations: (To be removed in RMagick 4.0)

- Support for Ruby 2.3
- `KernelInfo#zero_nans` (#531) (no replacement)
- `KernelInfo#show` (#532) (no replacement)
- `ImageList#fx` (#529) (use `Image#fx` instead)
- `Image#alpha=` (#530) (use `Image#alpha` instead)
- `Image#mask=` (#530) (use `Image#mask` instead)
- `Image#matte` (#530) (use `Image#alpha` instead)
- `Image#matte=` (#530) (use `Image#alpha` instead)

Enhancements:

- Support ruby-mswin environment on Windows (#425)
- Add test for supporting webp format (#406)
- Add explicit Ruby 2.5 support (#339)
- Add explicit Ruby 2.6 support (#467)
- Restore support for ImageMagick 6.7 (#475)
- Add explicit ImageMagick 6.9 support (#340)
- Work towards ImageMagick 7.0 support (#470) (#487) (#489) (#492) (#494)
- Improve error messaging (#480) (#517)
- Add TimeResource support (#402)
- Add Image#fx method (#529)

Bug Fixes:

- Many, many memory leaks fixed
  (#362) (#361) (#360) (#359) (#358) (#357) (#367) (#370) (#364) (#372) (#373)
  (#374) (#375) (#376) (#385) (#384) (#383) (#382) (#381) (#380) (#379) (#378)
  (#377) (#391) (#390) (#389) (#396) (#401) (#409) (#419) (#417) (#416) (#415)
  (#414) (#413) (#412) (#411) (#410) (#418) (#454) (#453) (#452) (#451) (#450)
  (#461) (#460) (#459) (#563)
- Fix SEGV in ImageList methods with invalid image list (#356)
- Fix SEGV in Image#recolor (#387)
- Fix SEGV in Image#profile! (#400)
- Fix build error on Homebrew environment (#426)
- Fix Image#quantize and ImageList#quantize could not make dither false (#458)
- Replace obsoleted $defout to $stdout (#463)
- Avoid SEGV in monitor feature for Ruby 2.5+ (#462)
- Fix SEGV in Image#write with CMYKColorspace (#465)
- Avoid problems related to GC in monitor feature (#468)
- Get rid of compiler warnings (#484) (#491) (#500)
- Fix rmfill leaks (#528)
- Removed automatic allocation of the ImageInfo that is broken. (#547)
- Fix color histogram (#540)
- Fix Image#iptc_profile does not work with ImageMagick 6.7 (#558)

Code Quality:

- Many tests written
- CI improvements
- Other refactors