$VARNAME is what we use for environment variables, it's good to
separate.
Some people use envsubst for homemade variable interpolation, it's also
good to have separation there.
## Changes
It covers both https://$DATABRICKS_HOST and http://$DATABRICKS_HOST so
the test output does not change between local and the cloud.
## Tests
Existing tests using golden files (acceptance and integration) catch
this and were updated.
## Changes
Add new type of test helpers that run the command and compare full
output (golden files approach).
In case of JSON, there is also an option to ignore certain paths.
Add test for different versions of Python to go through bundle init
default-python / validate / deploy / summary.
## Tests
New integration tests.
Denis Bilenko