devel/ruby-celluloid: update to 0.18.0

0.18.0 (2020-12-05)

#804 Remove deprecation warnings

#802 Remove lattice link itself.

#797 Update Ruby versions in CI script

#801 Associate Open Collective sponsorship option

#800 Streamline README

#799 Update links, add diagram preview.

#796 Create Class Diagram in Draw.io

#798 Pertinent Newsflash

#792 CI: 2.5.5, 2.6.2

#788 Travis: Include Ruby 2.5, 2.6

#787 Travis config: drop old configuration sudo: false

#786 Travis: use jruby-9.2.5.0

#783 v0.18.0.pre2

#782 Merge 'celluloid-supervision' back into the tree

#781 .gitmodules: No longer used

#780 README.md: Link to unmaintained issue

#778 README.md: Add "maintained: no! (as of 2016)" badge

#777 gemspec: Metadata with supported links

#776 Travis: use jruby-9.2.0.0

#775 Travis: jruby-9.1.17.0

#769 Travis: jruby-9.1.15.0

#768 Travis: use latest JRuby

#767 CHANGES: Add GitHub compare link on each heading

#766 Fix celluloid/celluloid#758

#765 Travis: jruby-9.1.13.0

#761 Travis: jruby-9.1.12.0

#760 Travis: jruby-9.1.10.0

#759 Travis: jruby-9.1.9.0

#757 parameterize error message so old and new Rubies match text

#756 Travis: latest stable rubies

#754 README: Fix badge rendering in Markdown

#753 Travis: use jruby-9.1.8.0

#752 Misspellings

#749 Return false from Celluloid.running? if Celluloid.boot hasn't been called

#751 Travis: Use JRuby 9.1.7.0

#740 Global variables: stop the bleeding

#739 Remove hacks around old MRIs, JRuby, and rbx

#738 Update to RuboCop 0.45.0 (with new rubocop.yml policy)

#737 Simplify dependencies: merge 'essentials' and 'culture' repos

#736 Remove $CELLULOID_BACKPORTED and $CELLULOID_MANAGED

#735 Require Ruby 2.2.6+

#729 Remove mysterious Fiber.yield

#721 Instruction for cloning Celluloid via github

#715 fix error response reference in Future#cancel

#712 Add RBX-3 to the build

#711 Added bundler cache

#709 Fix autostart. Fixes https://github.com/celluloid/celluloid/issues/698

#705 Adding method source code path to backtrace

(taca)