`explain()` sometimes marks up very long string with `^`

[joelostblom]

In this example:

import check_datapackage as cdp
package_properties = cdp.example_package_properties()
del package_properties["resources"]
cdp.check(properties=package_properties, error=True)

The entire resource value is marked with ^

While correct, this is not helpful and looks confusing. One possible solution would be to truncate long objects/values as .... This would not only be helpful for explain() but also avoid that we clutter the output if there is a huge input dictionary/json. So the output in this case would looks something like this (truncating everything between the first and last key):

At resources:
|
| resources: {'name': 'woolly-dormice' ... 'licenses': [{'name': 'odc-pddl'}]}
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
'resources' is a required property

It would be interesting to investigate what other software package that use ^ for errors do in these situations.

[lwjohnst86]

Also, I feel like that is the wrong output... That content shown in resources is actually the full package metadata.

I also think this is an issue with how to show "required" properties. For missing required properties, it might be useful to just show "resources: " or something similar.