Replace godep with vndr

Vndr has a simpler configuration and allows pointing to forked
packages. Additionally other docker projects are now using
vndr making vendoring in distribution more consistent.

Updates letsencrypt to use fork.
No longer uses sub-vendored packages.

Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)

vendor/github.com/miekg/dns/reverse.go

@@ -0,0 +1,38 @@
+package dns
+
+// StringToType is the reverse of TypeToString, needed for string parsing.
+var StringToType = reverseInt16(TypeToString)
+
+// StringToClass is the reverse of ClassToString, needed for string parsing.
+var StringToClass = reverseInt16(ClassToString)
+
+// Map of opcodes strings.
+var StringToOpcode = reverseInt(OpcodeToString)
+
+// Map of rcodes strings.
+var StringToRcode = reverseInt(RcodeToString)
+
+// Reverse a map
+func reverseInt8(m map[uint8]string) map[string]uint8 {
+	n := make(map[string]uint8, len(m))
+	for u, s := range m {
+		n[s] = u
+	}
+	return n
+}
+
+func reverseInt16(m map[uint16]string) map[string]uint16 {
+	n := make(map[string]uint16, len(m))
+	for u, s := range m {
+		n[s] = u
+	}
+	return n
+}
+
+func reverseInt(m map[int]string) map[string]int {
+	n := make(map[string]int, len(m))
+	for u, s := range m {
+		n[s] = u
+	}
+	return n
+}