Moves to official vendoring solution

vendor/github.com/onsi/gomega/matchers/contain_element_matcher.go

@@ -0,0 +1,56 @@
+package matchers
+
+import (
+	"fmt"
+	"reflect"
+
+	"github.com/onsi/gomega/format"
+)
+
+type ContainElementMatcher struct {
+	Element interface{}
+}
+
+func (matcher *ContainElementMatcher) Match(actual interface{}) (success bool, err error) {
+	if !isArrayOrSlice(actual) && !isMap(actual) {
+		return false, fmt.Errorf("ContainElement matcher expects an array/slice/map.  Got:\n%s", format.Object(actual, 1))
+	}
+
+	elemMatcher, elementIsMatcher := matcher.Element.(omegaMatcher)
+	if !elementIsMatcher {
+		elemMatcher = &EqualMatcher{Expected: matcher.Element}
+	}
+
+	value := reflect.ValueOf(actual)
+	var keys []reflect.Value
+	if isMap(actual) {
+		keys = value.MapKeys()
+	}
+	var lastError error
+	for i := 0; i < value.Len(); i++ {
+		var success bool
+		var err error
+		if isMap(actual) {
+			success, err = elemMatcher.Match(value.MapIndex(keys[i]).Interface())
+		} else {
+			success, err = elemMatcher.Match(value.Index(i).Interface())
+		}
+		if err != nil {
+			lastError = err
+			continue
+		}
+		if success {
+			return true, nil
+		}
+	}
+
+	return false, lastError
+}
+
+func (matcher *ContainElementMatcher) FailureMessage(actual interface{}) (message string) {
+	return format.Message(actual, "to contain element matching", matcher.Element)
+}
+
+func (matcher *ContainElementMatcher) NegatedFailureMessage(actual interface{}) (message string) {
+	return format.Message(actual, "not to contain element matching", matcher.Element)
+}