vendor: update all dependencies

vendor/github.com/spf13/cobra/README.md

@@ -192,6 +192,13 @@ var rootCmd = &cobra.Command{
     // Do Stuff Here
   },
 }
+
+func Execute() {
+  if err := rootCmd.Execute(); err != nil {
+    fmt.Println(err)
+    os.Exit(1)
+  }
+}
 ```
 
 You will additionally define flags and handle configuration in your init() function.
@@ -337,8 +344,8 @@ rootCmd.Flags().StringVarP(&Source, "source", "s", "", "Source directory to read
 
 ### Local Flag on Parent Commands
 
-By default Cobra only parses local flags on the target command, any local flags on 
-parent commands are ignored. By enabling `Command.TraverseChildren` Cobra will 
+By default Cobra only parses local flags on the target command, any local flags on
+parent commands are ignored. By enabling `Command.TraverseChildren` Cobra will
 parse local flags on each command before executing the target command.
 
 ```go
@@ -366,6 +373,15 @@ when the `--author` flag is not provided by user.
 
 More in [viper documentation](https://github.com/spf13/viper#working-with-flags).
 
+### Required flags
+
+Flags are optional by default. If instead you wish your command to report an error
+when a flag has not been set, mark it as required:
+```go
+rootCmd.Flags().StringVarP(&Region, "region", "r", "", "AWS region (required)")
+rootCmd.MarkFlagRequired("region")
+```
+
 ## Positional and Custom Arguments
 
 Validation of positional arguments can be specified using the `Args` field