Add "Back to votes" button

Allows navigation by buttons between the votes and results page
Updates database migration history

Should now allow database to auto-update.
If any issues arise, run "Update-Database" in the package manager console
Re-enable migrations
Re-enable highlighting of selected vote

Highlights the last voted option, if it exists.
Merge pull request #42 from tpkelly/develop

Minor fixes
Deleting options now deletes relevant votes
Merge pull request #44 from stevenhillcox/fix/delete-option-votes

Deleting options now deletes relevant votes
Merge pull request #43 from Generic-Voting-Application/develop

Release 0.2.1