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/helper.go

@@ -0,0 +1,71 @@
+// Copyright (c) 2017, A. Stoewer <adrian.stoewer@rz.ifi.lmu.de>
+// All rights reserved.
+
+package strcase
+
+// isLower checks if a character is lower case. More precisely it evaluates if it is
+// in the range of ASCII character 'a' to 'z'.
+func isLower(ch rune) bool {
+	return ch >= 'a' && ch <= 'z'
+}
+
+// toLower converts a character in the range of ASCII characters 'A' to 'Z' to its lower
+// case counterpart. Other characters remain the same.
+func toLower(ch rune) rune {
+	if ch >= 'A' && ch <= 'Z' {
+		return ch + 32
+	}
+	return ch
+}
+
+// isLower checks if a character is upper case. More precisely it evaluates if it is
+// in the range of ASCII characters 'A' to 'Z'.
+func isUpper(ch rune) bool {
+	return ch >= 'A' && ch <= 'Z'
+}
+
+// toLower converts a character in the range of ASCII characters 'a' to 'z' to its lower
+// case counterpart. Other characters remain the same.
+func toUpper(ch rune) rune {
+	if ch >= 'a' && ch <= 'z' {
+		return ch - 32
+	}
+	return ch
+}
+
+// isSpace checks if a character is some kind of whitespace.
+func isSpace(ch rune) bool {
+	return ch == ' ' || ch == '\t' || ch == '\n' || ch == '\r'
+}
+
+// isDelimiter checks if a character is some kind of whitespace or '_' or '-'.
+func isDelimiter(ch rune) bool {
+	return ch == '-' || ch == '_' || isSpace(ch)
+}
+
+// iterFunc is a callback that is called fro a specific position in a string. Its arguments are the
+// rune at the respective string position as well as the previous and the next rune. If curr is at the
+// first position of the string prev is zero. If curr is at the end of the string next is zero.
+type iterFunc func(prev, curr, next rune)
+
+// stringIter iterates over a string, invoking the callback for every single rune in the string.
+func stringIter(s string, callback iterFunc) {
+	var prev rune
+	var curr rune
+	for _, next := range s {
+		if curr == 0 {
+			prev = curr
+			curr = next
+			continue
+		}
+
+		callback(prev, curr, next)
+
+		prev = curr
+		curr = next
+	}
+
+	if len(s) > 0 {
+		callback(prev, curr, 0)
+	}
+}