#48 - Add release notes to Femah.Core NuGet package when publishing.

Began implementation of the 'Publish' phase of the deployment pipeline.
- Added psake tasks and a Powershell module to update the Github.com release 'tag_name' and 'draft' (published) status for the current build, using the Github API.  This provides the ability to fully automate the 'Publish' phase of the deployment pipeline that publishes the Nuget and Symbol packages to nuget.org and symbolsource.org respectively.