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/steveyen/gtreap/README.md

@@ -1,90 +0,0 @@
-gtreap
-------
-
-gtreap is an immutable treap implementation in the Go Language
-
-[![GoDoc](https://godoc.org/github.com/steveyen/gtreap?status.svg)](https://godoc.org/github.com/steveyen/gtreap) [![Build Status](https://drone.io/github.com/steveyen/gtreap/status.png)](https://drone.io/github.com/steveyen/gtreap/latest) [![Coverage Status](https://coveralls.io/repos/steveyen/gtreap/badge.png)](https://coveralls.io/r/steveyen/gtreap)
-
-Overview
-========
-
-gtreap implements an immutable treap data structure in golang.
-
-By treap, this data structure is both a heap and a binary search tree.
-
-By immutable, any updates/deletes to a treap will return a new treap
-which can share internal nodes with the previous treap.  All nodes in
-this implementation are read-only after their creation.  This allows
-concurrent readers to operate safely with concurrent writers as
-modifications only create new data structures and never modify
-existing data structures.  This is a simple approach to achieving MVCC
-or multi-version concurrency control.
-
-By heap, items in the treap follow the heap-priority property, where a
-parent node will have higher priority than its left and right children
-nodes.
-
-By binary search tree, items are store lexigraphically, ordered by a
-user-supplied Compare function.
-
-To get a probabilistic O(lg N) tree height, you should use a random
-priority number during the Upsert() operation.
-
-LICENSE
-=======
-
-MIT
-
-Example
-=======
-
-    import (
-        "math/rand"
-        "github.com/steveyen/gtreap"
-    )
-    
-    func stringCompare(a, b interface{}) int {
-	    return bytes.Compare([]byte(a.(string)), []byte(b.(string)))
-    }
-    
-    t := gtreap.NewTreap(stringCompare)
-    t = t.Upsert("hi", rand.Int())
-    t = t.Upsert("hola", rand.Int())
-    t = t.Upsert("bye", rand.Int())
-    t = t.Upsert("adios", rand.Int())
-    
-    hi = t.Get("hi")
-    bye = t.Get("bye")
-    
-    // Some example Delete()'s...
-    t = t.Delete("bye")
-    nilValueHere = t.Get("bye")
-    t2 = t.Delete("hi")
-    nilValueHere2 = t2.Get("hi")
-    
-    // Since we still hold onto treap t, we can still access "hi".
-    hiStillExistsInTreapT = t.Get("hi")
-    
-    t.VisitAscend("cya", func(i Item) bool {
-        // This visitor callback will be invoked with every item
-        // from "cya" onwards.  So: "hi", "hola".
-        // If we want to stop visiting, return false;
-        // otherwise a true return result means keep visiting items.
-        return true
-    })
-
-Tips
-====
-
-The Upsert() method takes both an Item (an interface{}) and a heap
-priority.  Usually, that priority should be a random int
-(math/rand.Int()) or perhaps even a hash of the item.  However, if you
-want to shuffle more commonly accessed items nearer to the top of the
-treap for faster access, at the potential cost of not approaching a
-probabilistic O(lg N) tree height, then you might tweak the priority.
-
-See also
-========
-
-For a simple, ordered, key-value storage or persistence library built
-on immutable treaps, see: https://github.com/steveyen/gkvlite