[BUG] moment version too restrictive

[sebastianhaeni]

Expected Behavior

The dependency on moment.js should be loosened to something like >=2.18.0 <3.0.0 since minor updates should not break the API of Chart.js.

Current Behavior

The restriction is on ~2.18.0. moment.js was recently updated to 2.19.1.

Context

If we have a dependency on moment.js in our own package.json and Chart.js has it's dependency, the likelihood of us using the same version is small. Deduping is not possible when a different minor version of moment.js is used.

A problem arised because we use webpack in our build process. Webpack bundled the separate version that Chart.js requires in a separate instance and thus didn't use the global locale settings anymore. So the time scales were always in English.

Environment

• Chart.js version: 2.7.0

[etimberg]

This was done in #4891