Migrate to dep (#3972)

* Update makefile to use dep

* Migrate to dep

* Fix some deps

* Try to find a better version for golang.org/x/net

* Try to find a better version for golang.org/x/oauth2

vendor/github.com/gorilla/securecookie/README.md

@@ -1,78 +0,0 @@
-securecookie
-============
-[![GoDoc](https://godoc.org/github.com/gorilla/securecookie?status.svg)](https://godoc.org/github.com/gorilla/securecookie) [![Build Status](https://travis-ci.org/gorilla/securecookie.png?branch=master)](https://travis-ci.org/gorilla/securecookie)
-
-securecookie encodes and decodes authenticated and optionally encrypted 
-cookie values.
-
-Secure cookies can't be forged, because their values are validated using HMAC.
-When encrypted, the content is also inaccessible to malicious eyes. It is still
-recommended that sensitive data not be stored in cookies, and that HTTPS be used
-to prevent cookie [replay attacks](https://en.wikipedia.org/wiki/Replay_attack).
-
-## Examples
-
-To use it, first create a new SecureCookie instance:
-
-```go
-// Hash keys should be at least 32 bytes long
-var hashKey = []byte("very-secret")
-// Block keys should be 16 bytes (AES-128) or 32 bytes (AES-256) long.
-// Shorter keys may weaken the encryption used.
-var blockKey = []byte("a-lot-secret")
-var s = securecookie.New(hashKey, blockKey)
-```
-
-The hashKey is required, used to authenticate the cookie value using HMAC.
-It is recommended to use a key with 32 or 64 bytes.
-
-The blockKey is optional, used to encrypt the cookie value -- set it to nil
-to not use encryption. If set, the length must correspond to the block size
-of the encryption algorithm. For AES, used by default, valid lengths are
-16, 24, or 32 bytes to select AES-128, AES-192, or AES-256.
-
-Strong keys can be created using the convenience function GenerateRandomKey().
-
-Once a SecureCookie instance is set, use it to encode a cookie value:
-
-```go
-func SetCookieHandler(w http.ResponseWriter, r *http.Request) {
-	value := map[string]string{
-		"foo": "bar",
-	}
-	if encoded, err := s.Encode("cookie-name", value); err == nil {
-		cookie := &http.Cookie{
-			Name:  "cookie-name",
-			Value: encoded,
-			Path:  "/",
-			Secure: true,
-			HttpOnly: true,
-		}
-		http.SetCookie(w, cookie)
-	}
-}
-```
-
-Later, use the same SecureCookie instance to decode and validate a cookie
-value:
-
-```go
-func ReadCookieHandler(w http.ResponseWriter, r *http.Request) {
-	if cookie, err := r.Cookie("cookie-name"); err == nil {
-		value := make(map[string]string)
-		if err = s2.Decode("cookie-name", cookie.Value, &value); err == nil {
-			fmt.Fprintf(w, "The value of foo is %q", value["foo"])
-		}
-	}
-}
-```
-
-We stored a map[string]string, but secure cookies can hold any value that
-can be encoded using `encoding/gob`. To store custom types, they must be
-registered first using gob.Register(). For basic types this is not needed;
-it works out of the box. An optional JSON encoder that uses `encoding/json` is
-available for types compatible with JSON.
-
-## License
-
-BSD licensed. See the LICENSE file for details.