Use apiextension v1

- upgrade from apiextension v1beta1 to v1
 - generate yaml manifest for crd intead of applying it at runtime
  - users will have to apply the manifest with kubectl
 - kg and kgctl log an error if the crd is not present
 - now validation should actually work

Signed-off-by: leonnicolas <leonloechner@gmx.de>

vendor/github.com/spf13/cobra/cobra.go

@@ -19,6 +19,7 @@ package cobra
 import (
 	"fmt"
 	"io"
+	"os"
 	"reflect"
 	"strconv"
 	"strings"
@@ -205,3 +206,17 @@ func stringInSlice(a string, list []string) bool {
 	}
 	return false
 }
+
+// CheckErr prints the msg with the prefix 'Error:' and exits with error code 1. If the msg is nil, it does nothing.
+func CheckErr(msg interface{}) {
+	if msg != nil {
+		fmt.Fprintln(os.Stderr, "Error:", msg)
+		os.Exit(1)
+	}
+}
+
+// WriteStringAndCheck writes a string into a buffer, and checks if the error is not nil.
+func WriteStringAndCheck(b io.StringWriter, s string) {
+	_, err := b.WriteString(s)
+	CheckErr(err)
+}