Incompatibility with npm 7

[jlkiri]

microbundle is not compatible with npm 7 (currently beta) in "normal" mode which respects peer deps.

$ npm i microbundle -D
npm ERR! code ERESOLVE
npm ERR! ERESOLVE unable to resolve dependency tree
npm ERR!
npm ERR! While resolving: @rollup/plugin-commonjs@13.0.2
npm ERR! Found: rollup@1.32.1
npm ERR! node_modules/rollup
npm ERR!   rollup@"^1.32.1" from microbundle@0.12.3
npm ERR!   node_modules/microbundle
npm ERR!     dev microbundle@"*" from the root project
npm ERR!   peer rollup@"^1.20.0||^2.0.0" from @rollup/plugin-alias@3.1.1
npm ERR!   node_modules/@rollup/plugin-alias
npm ERR!     @rollup/plugin-alias@"^3.1.1" from microbundle@0.12.3
npm ERR!     node_modules/microbundle
npm ERR!       dev microbundle@"*" from the root project
npm ERR!   6 more (@rollup/plugin-babel, @rollup/plugin-json, ...)
npm ERR!
npm ERR! Could not add conflicting dependency: rollup@2.28.2
npm ERR! node_modules/rollup
npm ERR!   peer rollup@"^2.3.4" from @rollup/plugin-commonjs@13.0.2
npm ERR!   node_modules/@rollup/plugin-commonjs
npm ERR!     @rollup/plugin-commonjs@"^13.0.0" from microbundle@0.12.3
npm ERR!     node_modules/microbundle
npm ERR!       dev microbundle@"*" from the root project
npm ERR!
npm ERR! Fix the upstream dependency conflict, or retry
npm ERR! this command with --legacy-peer-deps
npm ERR! to accept an incorrect (and potentially broken) dependency resolution.

This is because microbundle uses rollup 1.32.1. @rollup/plugin-commonjs which microbundle also uses has rollup ^2.3.4 as its peer.

[developit]

This is fixed in npm 7.0.7, and will be addressed in Microbundle by #738.