Switch to dep for dependency management

vendor/github.com/lib/pq/ssl_renegotiation.go

@@ -0,0 +1,8 @@
+// +build !go1.7
+
+package pq
+
+import "crypto/tls"
+
+// Renegotiation is not supported by crypto/tls until Go 1.7.
+func sslRenegotiation(*tls.Config) {}