Look for usable on-cluster credentials using k8schain (#243)

* dep ensure and use k8schain

* checkpoint

* fix vendoring, stuff builds

* Use k8schain for pushes too

* Use NewNoClient

* update ggcr dep

* Move k8schain usage to image_util.go

vendor/github.com/json-iterator/go/any_float.go

@@ -0,0 +1,83 @@
+package jsoniter
+
+import (
+	"strconv"
+)
+
+type floatAny struct {
+	baseAny
+	val float64
+}
+
+func (any *floatAny) Parse() *Iterator {
+	return nil
+}
+
+func (any *floatAny) ValueType() ValueType {
+	return NumberValue
+}
+
+func (any *floatAny) MustBeValid() Any {
+	return any
+}
+
+func (any *floatAny) LastError() error {
+	return nil
+}
+
+func (any *floatAny) ToBool() bool {
+	return any.ToFloat64() != 0
+}
+
+func (any *floatAny) ToInt() int {
+	return int(any.val)
+}
+
+func (any *floatAny) ToInt32() int32 {
+	return int32(any.val)
+}
+
+func (any *floatAny) ToInt64() int64 {
+	return int64(any.val)
+}
+
+func (any *floatAny) ToUint() uint {
+	if any.val > 0 {
+		return uint(any.val)
+	}
+	return 0
+}
+
+func (any *floatAny) ToUint32() uint32 {
+	if any.val > 0 {
+		return uint32(any.val)
+	}
+	return 0
+}
+
+func (any *floatAny) ToUint64() uint64 {
+	if any.val > 0 {
+		return uint64(any.val)
+	}
+	return 0
+}
+
+func (any *floatAny) ToFloat32() float32 {
+	return float32(any.val)
+}
+
+func (any *floatAny) ToFloat64() float64 {
+	return any.val
+}
+
+func (any *floatAny) ToString() string {
+	return strconv.FormatFloat(any.val, 'E', -1, 64)
+}
+
+func (any *floatAny) WriteTo(stream *Stream) {
+	stream.WriteFloat64(any.val)
+}
+
+func (any *floatAny) GetInterface() interface{} {
+	return any.val
+}