For supporting more region I added the signature_version property to NoDB class.
e.g.: The original branch did not supported Frankfurt (eu-central-1) region
Coverage increased (+0.5%) to 51.613% when pulling 44c9ec853b1b1b34fac5ac1ab1419de67c0cc0bd on szilagyiabo:master into 33a544040e2b0f2636ec8ba11b1b292ed0681010 on Miserlou:master.
For supporting more region I added the signature_version property to NoDB class. e.g.: The original branch did not supported Frankfurt (eu-central-1) region