Fix integration with rollup-plugin-commonjs

[chasenlehara]

steal-tools started to break as of [email protected] with this error:

TypeError: Cannot read property 'load' of undefined
 at exports.moduleNameFromSpecifier (lib/node/dependency_resolver.js:9:194)
 at resolveId (lib/bundle/concat_source_es.js:9:2882)
 at node_modules/steal-rollup/dist/rollup.js:5980:113

As far as I know, this isn’t a bug on their end and we need to fix our integration with that package.

Here’s the issue Greenkeeper originally filed: #1121

For now, we have this semver range to avoid the issue:

steal-tools/package.json

Line 33 in 003ec65

"rollup-plugin-commonjs": "<=9.3.2",