Bump modules package version to 0.8.1-beta.4.
Bump modules package version to 0.8.1-beta.4.

The 0.8.0 version line was colliding with release-1.5, causing the modules
package not to be published during the release-1.4.3.x release process,
similar to what was happening with the ecmascript package:
https://github.com/meteor/meteor/issues/8423#issuecomment-287332131

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