Adding Concurrency in Pool Manager (#1698)

Concurrency in the pool manager allows specializing pods concurrently based on a specified limit. 

Co-authored-by: Vishal <vishal-biyani@users.noreply.github.com>

pkg/fission-cli/cmd/function/update.go

@@ -155,6 +155,10 @@ func (opts *UpdateSubCommand) complete(input cli.Input) error {
 		function.Spec.IdleTimeout = &fnTimeout
 	}
 
+	if input.IsSet(flagkey.FnConcurrency) {
+		function.Spec.Concurrency = input.Int(flagkey.FnConcurrency)
+	}
+
 	if len(pkgName) == 0 {
 		pkgName = function.Spec.Package.PackageRef.Name
 	}