Release 0.7.5 (#70)

* Resolve issue with opaque tokens not being parsed correctly

* Increase test coverage

* Further improvements to test coverage and code quality

* Add new providers.

* fixup! Add new providers.

* Cleanup.

* fixup! Cleanup.

* fixup! fixup! Cleanup.

* fixup! fixup! fixup! Cleanup.

* fixup! fixup! fixup! fixup! Cleanup.

* Memory management optimisation

24 bytes per Put < 256-4096 bytes per buffer allocation avoided (10-170x difference)

* Pooling cleanup.

error_recovery.go

@@ -963,7 +963,7 @@ func (gd *GracefulDegradation) Close() {
 			// Don't set to nil to avoid race conditions
 		}
 
-		gd.logger.Info("GracefulDegradation shut down successfully")
+		gd.logger.Debug("GracefulDegradation shut down successfully")
 	})
 }