Update AWS Go SDK To v1.25.35 (#307)

Fixes STS regional endpoint support.

go.mod

@@ -3,7 +3,7 @@ module github.com/segmentio/aws-okta
 require (
 	github.com/99designs/keyring v1.0.0
 	github.com/alessio/shellescape v0.0.0-20190409004728-b115ca0f9053
-	github.com/aws/aws-sdk-go v1.25.25
+	github.com/aws/aws-sdk-go v1.25.35
 	github.com/bmizerany/assert v0.0.0-20160611221934-b7ed37b82869 // indirect
 	github.com/inconshreveable/mousetrap v1.0.0 // indirect
 	github.com/karalabe/hid v1.0.0 // indirect

go.sum

@@ -2,8 +2,8 @@ github.com/99designs/keyring v1.0.0 h1:O2nCc8QRO2yeO7ncdR7bd17cdofhM8AXug42ahzEs
 github.com/99designs/keyring v1.0.0/go.mod h1:qVCfjMddwdzjgy848stNe9eTPmovvxF1lhJvOD6LUEo=
 github.com/alessio/shellescape v0.0.0-20190409004728-b115ca0f9053 h1:H/GMMKYPkEIC3DF/JWQz8Pdd+Feifov2EIgGfNpeogI=
 github.com/alessio/shellescape v0.0.0-20190409004728-b115ca0f9053/go.mod h1:xW8sBma2LE3QxFSzCnH9qe6gAE2yO9GvQaWwX89HxbE=
-github.com/aws/aws-sdk-go v1.25.25 h1:j3HLOqcDWjNox1DyvJRs+kVQF42Ghtv6oL6cVBfXS3U=
-github.com/aws/aws-sdk-go v1.25.25/go.mod h1:KmX6BPdI08NWTb3/sm4ZGu5ShLoqVDhKgpiN924inxo=
+github.com/aws/aws-sdk-go v1.25.35 h1:fe2tJnqty/v/50pyngKdNk/NP8PFphYDA1Z7N3EiiiE=
+github.com/aws/aws-sdk-go v1.25.35/go.mod h1:KmX6BPdI08NWTb3/sm4ZGu5ShLoqVDhKgpiN924inxo=
 github.com/bmizerany/assert v0.0.0-20160611221934-b7ed37b82869 h1:DDGfHa7BWjL4YnC6+E63dPcxHo2sUxDIu8g3QgEJdRY=
 github.com/bmizerany/assert v0.0.0-20160611221934-b7ed37b82869/go.mod h1:Ekp36dRnpXw/yCqJaO+ZrUyxD+3VXMFFr56k5XYrpB4=
 github.com/danieljoos/wincred v1.0.2 h1:zf4bhty2iLuwgjgpraD2E9UbvO+fe54XXGJbOwe23fU=