CHANGELOG.md: updates for SDK's switch to go modules

Author: joelanford

CHANGELOG.md

@@ -10,6 +10,7 @@
 - Scaffold a `pkg/apis/<group>/group.go` package file to avoid `go/build` errors when running Kubernetes code generators. ([#1401](https://github.com/operator-framework/operator-sdk/pull/1401))
 - Adds a new extra variable containing the unmodified CR spec for ansible based operators. [#1563](https://github.com/operator-framework/operator-sdk/pull/1563)
 - New flag `--repo` for subcommands [`new`](https://github.com/operator-framework/operator-sdk/blob/master/doc/sdk-cli-reference.md#new) and [`migrate`](https://github.com/operator-framework/operator-sdk/blob/master/doc/sdk-cli-reference.md#migrate) specifies the repository path to be used in Go source files generated by the SDK. This flag can only be used with [Go modules](https://github.com/golang/go/wiki/Modules). ([#1475](https://github.com/operator-framework/operator-sdk/pull/1475))
+- Adds `go.mod` and `go.sum` to switch from `dep` to [Go modules](https://github.com/golang/go/wiki/Modules) to manage dependencies for the SDK project itself. ([#1566](https://github.com/operator-framework/operator-sdk/pull/1566))
 
 ### Changed
 
@@ -22,6 +23,7 @@
 ### Removed
 
 - The SDK no longer depends on a `vendor/` directory to manage dependencies *only if* using [Go modules](https://github.com/golang/go/wiki/Modules). The SDK and operator projects will only use vendoring if using `dep`, or modules and a `vendor/` dir is present. ([#1519](https://github.com/operator-framework/operator-sdk/pull/1519))
+- Removes `Gopkg.toml` and `Gopkg.lock` to drop the use of `dep` in favor of [Go modules](https://github.com/golang/go/wiki/Modules) to manage dependencies for the SDK project itself. ([#1566](https://github.com/operator-framework/operator-sdk/pull/1566))
 
 ### Bug Fixes