build: move e2e dependencies into e2e/go.mod

Several packages are only used while running the e2e suite. These
packages are less important to update, as the they can not influence the
final executable that is part of the Ceph-CSI container-image.

By moving these dependencies out of the main Ceph-CSI go.mod, it is
easier to identify if a reported CVE affects Ceph-CSI, or only the
testing (like most of the Kubernetes CVEs).

Signed-off-by: Niels de Vos <ndevos@ibm.com>

e2e/vendor/github.com/stoewer/go-strcase/camel.go

@@ -0,0 +1,40 @@
+// Copyright (c) 2017, A. Stoewer <adrian.stoewer@rz.ifi.lmu.de>
+// All rights reserved.
+
+package strcase
+
+import (
+	"strings"
+)
+
+// UpperCamelCase converts a string into camel case starting with a upper case letter.
+func UpperCamelCase(s string) string {
+	return camelCase(s, true)
+}
+
+// LowerCamelCase converts a string into camel case starting with a lower case letter.
+func LowerCamelCase(s string) string {
+	return camelCase(s, false)
+}
+
+func camelCase(s string, upper bool) string {
+	s = strings.TrimSpace(s)
+	buffer := make([]rune, 0, len(s))
+
+	stringIter(s, func(prev, curr, next rune) {
+		if !isDelimiter(curr) {
+			if isDelimiter(prev) || (upper && prev == 0) {
+				buffer = append(buffer, toUpper(curr))
+			} else if isLower(prev) {
+				buffer = append(buffer, curr)
+			} else if isUpper(prev) && isUpper(curr) && isLower(next) {
+				// Assume a case like "R" for "XRequestId"
+				buffer = append(buffer, curr)
+			} else {
+				buffer = append(buffer, toLower(curr))
+			}
+		}
+	})
+
+	return string(buffer)
+}