Support .mjs modules (as well as .js and .jsx) in ecmascript plugin.
Support .mjs modules (as well as .js and .jsx) in ecmascript plugin.

https://github.com/meteor/meteor/pull/10522#issuecomment-505553025

Hansoft/meteor,Hansoft/meteor,Hansoft/meteor,Hansoft/meteor,Hansoft/meteor,Hansoft/meteor,Hansoft/meteor