vendor: explicitly vendor golang.org/x/sys

Vendor golang.org/x/sys to get the UtimesNanoAt function defined for all
unix-like OSes. The function will be used in a successive commit.

This also re-vendors the other dependencies from glide.yaml.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>

vendor/golang.org/x/crypto/openpgp/packet/config.go

@@ -43,9 +43,6 @@ type Config struct {
 	// use a value that is at least 65536. See RFC 4880 Section
 	// 3.7.1.3.
 	S2KCount int
-	// RSABits is the number of bits in new RSA keys made with NewEntity.
-	// If zero, then 2048 bit keys are created.
-	RSABits int
 }
 
 func (c *Config) Random() io.Reader {