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/github.com/aws/aws-sdk-go/private/model/api/eventstream.go

@@ -0,0 +1,28 @@
+// +build codegen
+
+package api
+
+func (a *API) suppressEventStreams() {
+	const eventStreamMemberName = "EventStream"
+
+	for name, op := range a.Operations {
+		outbound := hasEventStream(op.InputRef.Shape)
+		inbound := hasEventStream(op.OutputRef.Shape)
+
+		if !(outbound || inbound) {
+			continue
+		}
+
+		a.removeOperation(name)
+	}
+}
+
+func hasEventStream(topShape *Shape) bool {
+	for _, ref := range topShape.MemberRefs {
+		if ref.Shape.IsEventStream {
+			return true
+		}
+	}
+
+	return false
+}