vendor: update all dependencies

* Update all dependencies
  * Remove all `[[constraint]]` from Gopkg.toml
  * Add in the minimum number of `[[override]]` to build
  * Remove go get of github.com/inconshreveable/mousetrap as it is vendored
  * Update docs with new policy on constraints

vendor/golang.org/x/crypto/xtea/block.go

@@ -50,7 +50,7 @@ func encryptBlock(c *Cipher, dst, src []byte) {
 	uint32ToBlock(v0, v1, dst)
 }
 
-// decryptBlock decrypt a single 8 byte block using XTEA.
+// decryptBlock decrypts a single 8 byte block using XTEA.
 func decryptBlock(c *Cipher, dst, src []byte) {
 	v0, v1 := blockToUint32(src)
 

vendor/golang.org/x/crypto/xtea/cipher.go

@@ -14,8 +14,8 @@ import "strconv"
 const BlockSize = 8
 
 // A Cipher is an instance of an XTEA cipher using a particular key.
-// table contains a series of precalculated values that are used each round.
 type Cipher struct {
+	// table contains a series of precalculated values that are used each round.
 	table [64]uint32
 }
 
@@ -54,7 +54,7 @@ func (c *Cipher) BlockSize() int { return BlockSize }
 // instead, use an encryption mode like CBC (see crypto/cipher/cbc.go).
 func (c *Cipher) Encrypt(dst, src []byte) { encryptBlock(c, dst, src) }
 
-// Decrypt decrypts the 8 byte buffer src using the key k and stores the result in dst.
+// Decrypt decrypts the 8 byte buffer src using the key and stores the result in dst.
 func (c *Cipher) Decrypt(dst, src []byte) { decryptBlock(c, dst, src) }
 
 // initCipher initializes the cipher context by creating a look up table