Ream fails to compile with newest Webpack due to missing uglifyjs
Webpack has recently replaced uglifyjs with terser: https://github.com/webpack-contrib/terser-webpack-plugin/issues/15

Ream has a hard-coded dependency for uglifyjs which is not listed in dependencies (which is a bad practice generally speaking), so fresh installs will fail. At the very least it should be added to dependencies, or better yet we should also migrate to terser.