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/josharian/intern/README.md

@@ -0,0 +1,5 @@
+Docs: https://godoc.org/github.com/josharian/intern
+
+See also [Go issue 5160](https://golang.org/issue/5160).
+
+License: MIT

e2e/vendor/github.com/josharian/intern/intern.go

@@ -0,0 +1,44 @@
+// Package intern interns strings.
+// Interning is best effort only.
+// Interned strings may be removed automatically
+// at any time without notification.
+// All functions may be called concurrently
+// with themselves and each other.
+package intern
+
+import "sync"
+
+var (
+	pool sync.Pool = sync.Pool{
+		New: func() interface{} {
+			return make(map[string]string)
+		},
+	}
+)
+
+// String returns s, interned.
+func String(s string) string {
+	m := pool.Get().(map[string]string)
+	c, ok := m[s]
+	if ok {
+		pool.Put(m)
+		return c
+	}
+	m[s] = s
+	pool.Put(m)
+	return s
+}
+
+// Bytes returns b converted to a string, interned.
+func Bytes(b []byte) string {
+	m := pool.Get().(map[string]string)
+	c, ok := m[string(b)]
+	if ok {
+		pool.Put(m)
+		return c
+	}
+	s := string(b)
+	m[s] = s
+	pool.Put(m)
+	return s
+}

e2e/vendor/github.com/josharian/intern/license.md

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2019 Josh Bleecher Snyder
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.