update action from nodejs:6 to nodejs:10

[dgrove-oss]

The installCatalog.sh script selects nodejs:6 as the runtime kind. NodeJS 6 is long past EOL; we need to update to select nodejs:10 instead.

The actual change is trivial, but travisci is not setup to actually do comprehensive testing of this repository, so verifying that the actions all still work with the sparser dependencies of the nodejs:10 kind is where the work is. Ideally, really travis testing would be configured as a side-effect of doing this work.