Use CircleCI Status badge instead of Insights.

Author: eresende-nuodb

NuoDb.EntityFrameworkCore.NuoDb/README.md

@@ -1,7 +1,7 @@
 nuodb-dotnet
 ============
 
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 This is the official NuoDB .NET driver. It is no longer actively supported by NuoDB. The driver will be updated and tested periodically.