Patch

[vHeemstra]

• Updates all dependencies.
  • Most importantly execa, which had a dependency on a version of cross-spawn that errors when used in worker threads (because of process.chdir()).
• Adds overrides for vulnerable nested dependencies (these can be remove once all the sub-dependencies have updated their dependencies, etc).
• Small renaming to be consistent with other imagemin plugins.

Fixes #41 #54 #55