style(viewer): fix lint error

test: update dependencies

ci: use node 12

feat: Upgrade to Angular 8

BREAKING CHANGE: Upgrade to Angular 8

ci: do nut publish viewer

fix: update dependencies to latest Angular 7 version

ci(travis): improve configuration

Closes Ritzlgrmft#15

docs(readme): fix links to api docs

test: update to jasmine 3

This includes an update of the dev dependency to zone.js

chore: update sematic-release