Deprecate SEO package in favor of Meteor-Dochead

[brylie]

We are currently using the Meteor SEO package in several places within our project. Determine whether it would be fruitful to deprecate the Meteor SEO package in favor of Meteor Dochead. If so, remove usage of Meteor SEO, including configuration file(s).

Specific file(s) include:

• /lib/_config/.seo.js - sets the global SEO options

Note: There does not appear to be any other reference to the SEO object in our project.

Related issue

• Set page title from within template created() callbacks #810 - start setting page title from within template created() callbacks to set the site title, etc., so that we have a relevant title on each page.