Address overview pages that do not meet content requirements

[sean1588]

We added a check to the registry to ensure the package overview page is not blank and also contains a minimal amount of content (at least 250 characters). We have added the current failing packages to an exceptions list for now in order to get the tests passing until these get addressed.

Here is a list of the current failures:

ERROR: The content in the overview file, themes/default/content/registry/packages/heroku/_index.md, does not meet the 250 character minimum requirement for content.
ERROR: The content in the overview file, themes/default/content/registry/packages/junipermist/_index.md, does not meet the 250 character minimum requirement for content.
ERROR: The content in the overview file, themes/default/content/registry/packages/meraki/_index.md, does not meet the 250 character minimum requirement for content.
ERROR: The content in the overview file, themes/default/content/registry/packages/packet/_index.md, does not meet the 250 character minimum requirement for content.
ERROR: The content in the overview file, themes/default/content/registry/packages/sdwan/_index.md, does not meet the 250 character minimum requirement for content.

We need to get heroku, junipermist, meraki, packet, and sdwan addessed.