Drop library-level constraints on tools (#36)

This drops library-level dependencies on tools used during development.
See also uber-go/atomic#65.

Note that we'll also tag a release when this lands.

Resolves #35

CHANGELOG.md

@@ -1,6 +1,12 @@
 Releases
 ========
 
+v1.5.0 (2020-02-24)
+===================
+
+-   Drop library dependency on development-time tooling.
+
+
 v1.4.0 (2019-11-04)
 ===================
 

go.mod

@@ -4,7 +4,7 @@ go 1.12
 
 require (
 	github.com/stretchr/testify v1.3.0
-	go.uber.org/atomic v1.5.0
+	go.uber.org/atomic v1.6.0
 	go.uber.org/tools v0.0.0-20190618225709-2cfd321de3ee
 	golang.org/x/lint v0.0.0-20190930215403-16217165b5de
 	golang.org/x/tools v0.0.0-20191029190741-b9c20aec41a5 // indirect

go.sum

@@ -15,8 +15,8 @@ github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFR
 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=
-go.uber.org/atomic v1.5.0 h1:OI5t8sDa1Or+q8AeE+yKeB/SDYioSHAgcVljj9JIETY=
-go.uber.org/atomic v1.5.0/go.mod h1:sABNBOSYdrvTF6hTgEIbc7YasKWGhgEQZyfxyTvoXHQ=
+go.uber.org/atomic v1.6.0 h1:Ezj3JGmsOnG1MoRWQkPBsKLe9DwWD9QeXzTRzzldNVk=
+go.uber.org/atomic v1.6.0/go.mod h1:sABNBOSYdrvTF6hTgEIbc7YasKWGhgEQZyfxyTvoXHQ=
 go.uber.org/tools v0.0.0-20190618225709-2cfd321de3ee h1:0mgffUl7nfd+FpvXMVz4IDEaUSmT1ysygQC7qYo7sG4=
 go.uber.org/tools v0.0.0-20190618225709-2cfd321de3ee/go.mod h1:vJERXedbb3MVM5f9Ejo0C68/HhF8uaILCdgjnY+goOA=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=