Relax version range of plugin-threshold peerDependencies

[pasieronen]

What's Changing and Why

The threshold plugin has peer dependencies color/resize plugins ^0.8.0, which does not match 0.9.5, and install from scratch complains:

$ npm install @jimp/plugin-threshold @jimp/plugin-color @jimp/plugin-resize @jimp/custom
npm WARN @jimp/plugin-threshold@0.9.5 requires a peer of @jimp/plugin-color@^0.8.0 but none is installed. You must install peer dependencies yourself.
npm WARN @jimp/plugin-threshold@0.9.5 requires a peer of @jimp/plugin-resize@^0.8.0 but none is installed. You must install peer dependencies yourself.

This PR changes the peer dependency version to >0.8.0.

What else might be affected

Tasks

• Add tests
• Update Documentation
• Update jimp.d.ts
• Add SemVer Label

[crutchcorn]

LGTM

[hipstersmoothie]

🚀 PR was released in v0.9.7 🚀