Merge pull request#1331 from mathjax/developThe new version 4.0

Update version to 4.0.0-rc.3 and latest SRE

Update version.ts

Update vesion.ts to current version

Try to fix Travis-CI to deply properly

Fix npm configuration so publishing works?

Merge pull request#974 from mathjax/v4.0-beta.3Update version to beta.3

Fix mj-context-menu dependencies

Update package scripts to avoid non-zero exit code

Update npm api_key