diff --git a/go.mod b/go.mod
index ed84906a..64a9e98f 100644
--- a/go.mod
+++ b/go.mod
@@ -47,11 +47,12 @@ require (
 	go.uber.org/atomic v1.3.2 // indirect
 	go.uber.org/multierr v1.1.0 // indirect
 	go.uber.org/zap v1.9.1 // indirect
-	golang.org/x/crypto v0.0.0-20190411191339-88737f569e3a // indirect
-	golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3 // indirect
+	golang.org/x/crypto v0.0.0-20190418165655-df01cb2cc480 // indirect
+	golang.org/x/image v0.0.0-20190417020941-4e30a6eb7d9a // indirect
+	golang.org/x/net v0.0.0-20190419010253-1f3472d942ba // indirect
 	golang.org/x/oauth2 v0.0.0-20190402181905-9f3314589c9a
 	golang.org/x/sync v0.0.0-20190412183630-56d357773e84 // indirect
-	golang.org/x/sys v0.0.0-20190412213103-97732733099d // indirect
+	golang.org/x/sys v0.0.0-20190419153524-e8e3143a4f4a // indirect
 	google.golang.org/appengine v1.5.0 // indirect
 	gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 // indirect
 	gopkg.in/ini.v1 v1.42.0 // indirect
diff --git a/go.sum b/go.sum
index bcad12bf..ad394d05 100644
--- a/go.sum
+++ b/go.sum
@@ -271,13 +271,15 @@ golang.org/x/crypto v0.0.0-20181030102418-4d3f4d9ffa16/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/crypto v0.0.0-20190411191339-88737f569e3a h1:Igim7XhdOpBnWPuYJ70XcNpq8q3BCACtVgNfoJxOV7g=
-golang.org/x/crypto v0.0.0-20190411191339-88737f569e3a/go.mod h1:WFFai1msRO1wXaEeE5yQxYXgSfI8pQAWXbQop6sCtWE=
+golang.org/x/crypto v0.0.0-20190418165655-df01cb2cc480 h1:O5YqonU5IWby+w98jVUG9h7zlCWCcH4RHyPVReBmhzk=
+golang.org/x/crypto v0.0.0-20190418165655-df01cb2cc480/go.mod h1:WFFai1msRO1wXaEeE5yQxYXgSfI8pQAWXbQop6sCtWE=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/image v0.0.0-20180708004352-c73c2afc3b81 h1:00VmoueYNlNz/aHIilyyQz/MHSqGoWJzpFv/HW8xpzI=
 golang.org/x/image v0.0.0-20180708004352-c73c2afc3b81/go.mod h1:ux5Hcp/YLpHSI86hEcLt0YII63i6oz57MZXIpbrjZUs=
 golang.org/x/image v0.0.0-20190321063152-3fc05d484e9f h1:FO4MZ3N56GnxbqxGKqh+YTzUWQ2sDwtFQEZgLOxh9Jc=
 golang.org/x/image v0.0.0-20190321063152-3fc05d484e9f/go.mod h1:kZ7UVZpmo3dzQBMxlp+ypCbDeSB+sBbTgSJuh5dn5js=
+golang.org/x/image v0.0.0-20190417020941-4e30a6eb7d9a h1:Rvz6SxvUYdeTtV9mm96imoWefLnhtz9Ac/gJfFfPzdc=
+golang.org/x/image v0.0.0-20190417020941-4e30a6eb7d9a/go.mod h1:kZ7UVZpmo3dzQBMxlp+ypCbDeSB+sBbTgSJuh5dn5js=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
 golang.org/x/lint v0.0.0-20190227174305-5b3e6a55c961/go.mod h1:wehouNa3lNwaWXcvxsM5YxQ5yQlVC4a0KAMCusXpPoU=
 golang.org/x/lint v0.0.0-20190301231843-5614ed5bae6f/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
@@ -295,8 +297,8 @@ golang.org/x/net v0.0.0-20190311183353-d8887717615a h1:oWX7TPOiFAMXLq8o0ikBYfCJV
 golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190328230028-74de082e2cca h1:hyA6yiAgbUwuWqtscNvWAI7U1CtlaD1KilQ6iudt1aI=
 golang.org/x/net v0.0.0-20190328230028-74de082e2cca/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
-golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3 h1:0GoQqolDA55aaLxZyTzK/Y2ePZzZTUrRacwib7cNsYQ=
-golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20190419010253-1f3472d942ba h1:h0zCzEL5UW1mERvwTN6AXcc75PpLkY6OcReia6Dq1BM=
+golang.org/x/net v0.0.0-20190419010253-1f3472d942ba/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/oauth2 v0.0.0-20190226205417-e64efc72b421/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
 golang.org/x/oauth2 v0.0.0-20190402181905-9f3314589c9a h1:tImsplftrFpALCYumobsd0K86vlAs/eXGFms2txfJfA=
@@ -319,8 +321,8 @@ golang.org/x/sys v0.0.0-20190222072716-a9d3bda3a223/go.mod h1:STP8DvDyc/dI5b8T5h
 golang.org/x/sys v0.0.0-20190329044733-9eb1bfa1ce65 h1:hOY+O8MxdkPV10pNf7/XEHaySCiPKxixMKUshfHsGn0=
 golang.org/x/sys v0.0.0-20190329044733-9eb1bfa1ce65/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190403152447-81d4e9dc473e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20190412213103-97732733099d h1:+R4KGOnez64A81RvjARKc4UT5/tI9ujCIVX+P5KiHuI=
-golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190419153524-e8e3143a4f4a h1:XCr/YX7O0uxRkLq2k1ApNQMims9eCioF9UpzIPBDmuo=
+golang.org/x/sys v0.0.0-20190419153524-e8e3143a4f4a/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/text v0.3.1-0.20180807135948-17ff2d5776d2 h1:z99zHgr7hKfrUcX/KsoJk5FJfjTceCKIp96+biqP4To=