Add dependency for Skybrud.Social.Core and Skybrud.Social.Google

[abjerner]

The dashboard currently has a dependency for Skybrud.Social, which contains both the core functionality as well as the Google/Analytics implementation.

In the future, Skybrud.Social will be replaced by Skybrud.Social.Core for the core functionality, and each service as it's own package - eg. Skybrud.Social.Google. This process isn't complete yet, but the Skybrud.Social dependency should be replaced by the two new packages before coming out of beta.