diff --git a/go.mod b/go.mod
index a7cda1892..ff0a7f33c 100644
--- a/go.mod
+++ b/go.mod
@@ -23,5 +23,6 @@ require (
 	golang.org/x/crypto v0.0.0-20190325154230-a5d413f7728c
 	golang.org/x/net v0.0.0-20190324223953-e3b2ff56ed87
 	golang.org/x/sys v0.0.0-20190322080309-f49334f85ddc // indirect
+	golang.org/x/tools v0.0.0-20190325223049-1d95b17f1b04 // indirect
 	gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 // indirect
 )
diff --git a/go.sum b/go.sum
index a0c040d35..259f98dfc 100644
--- a/go.sum
+++ b/go.sum
@@ -52,6 +52,7 @@ golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnf
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20190325154230-a5d413f7728c h1:Vj5n4GlwjmQteupaxJ9+0FNOmBrHfq7vN4btdGoDZgI=
 golang.org/x/crypto v0.0.0-20190325154230-a5d413f7728c/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190324223953-e3b2ff56ed87 h1:yh5/K199RObPR6zqVBYf+AyJuweAqx+fOe9s3cekn1Y=
 golang.org/x/net v0.0.0-20190324223953-e3b2ff56ed87/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
@@ -63,5 +64,7 @@ golang.org/x/sys v0.0.0-20190322080309-f49334f85ddc h1:4gbWbmmPFp4ySWICouJl6emP0
 golang.org/x/sys v0.0.0-20190322080309-f49334f85ddc/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/tools v0.0.0-20190325223049-1d95b17f1b04 h1:SRYGE+BqJRgY8JH4p2NmwTPeuREKqKYw5IuEmthTHKQ=
+golang.org/x/tools v0.0.0-20190325223049-1d95b17f1b04/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=