Change airbnb eslint config package to `eslint-config-airbnb-base` and update plugins.

Change `airbnb` to `airbnb-base` for .eslintrc `extends` value.

Added changelog entry

Made sure all plugins and envs are set

Corrected new failing specs

Adds tests.
Changes instance into a constructor

Adds tests for environments component

Adds tests assertations

Adds external URL test

Adds tests for Rollback component

Adds tests for stop component

Adds tests for actions component
Fix environment item

Init environment item tests