v0.1.5

• Allow Jekyll 4.x dependency range (#12) @SUPERCILEX
• update documentation for Jekyll 3.5.0+ (#9) @kenman345
• Appease Rubocop 0.51 (#6) @DirtyF
• Update copyright notice (#8) @DirtyF
• CI: test against Ruby 2.4 (#7) @DirtyF