diff --git a/.travis.yml b/.travis.yml
index efb68685..9bcff110 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,16 +1,16 @@
 language: go
 
 go:
-  - 1.12
-  - 1.11
-  - tip 
+  - 1.12.x
+  - 1.11.x
+  - tip
 
 env: GO111MODULE=on
 
 before_install:
   - go mod download
 
-install: 
+install:
   - go get golang.org/x/lint/golint
   - go get github.com/haya14busa/goverage
 
@@ -28,9 +28,9 @@ before_script:
 
 script:
   - diff -u <(echo -n) <(gofmt -d ./)                              # Fail if a .go file hasn't been formatted with gofmt
-  - goverage -v -covermode=atomic -coverprofile=coverage.txt $PKGS # Run all tests with coverage 
+  - goverage -v -covermode=atomic -coverprofile=coverage.txt $PKGS # Run all tests with coverage
   - go vet -v ./...                                                # static analyisis
   - golint $LINT_PKGS                                              # lint - ignore failures for now
-  
+
 after_success:
   - bash <(curl -s https://codecov.io/bash)
diff --git a/go.mod b/go.mod
index 86401c1b..d919f594 100644
--- a/go.mod
+++ b/go.mod
@@ -1,8 +1,8 @@
 module github.com/aws/aws-lambda-go
 
+go 1.12
+
 require (
-	github.com/davecgh/go-spew v1.1.0 // indirect
-	github.com/pmezard/go-difflib v1.0.0 // indirect
-	github.com/stretchr/testify v1.2.1
+	github.com/stretchr/testify v1.3.0
 	gopkg.in/urfave/cli.v1 v1.20.0
 )
diff --git a/go.sum b/go.sum
index c9a878ca..1e7eb83a 100644
--- a/go.sum
+++ b/go.sum
@@ -2,7 +2,8 @@ github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/stretchr/testify v1.2.1 h1:52QO5WkIUcHGIR7EnGagH88x1bUzqGXTC5/1bDTUQ7U=
-github.com/stretchr/testify v1.2.1/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=
+github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 gopkg.in/urfave/cli.v1 v1.20.0 h1:NdAVW6RYxDif9DhDHaAortIu956m2c0v+09AZBPTbE0=
 gopkg.in/urfave/cli.v1 v1.20.0/go.mod h1:vuBzUtMdQeixQj8LVd+/98pzhxNGQoyuPBlsXHOQNO0=