Remove support for Go < 1.13

.github/workflows/go-cross.yml

@@ -17,7 +17,7 @@ jobs:
 
     strategy:
       matrix:
-        go-version: [ "1.11", "1.12", "1.16", "1.18", "1.20", "1.x" ]
+        go-version: [ "1.13", "1.16", "1.18", "1.20", "1.x" ]
         os: [ubuntu-latest, macos-latest, windows-latest]
 
     steps:

README.md

@@ -18,6 +18,8 @@ Github user [@mna][6] created the package in April 2015, and [@breml][5] is the
 
 ### Breaking Changes since v1.0.0
 
+* Removed support for Go < v1.13 to support recent version of `golang.org/x/tools`.
+
 * Removed support for Go < v1.11 to support go modules for dependency tracking.
 
 * Removed support for Go < v1.9 due to the requirement [golang.org/x/tools/imports](https://godoc.org/golang.org/x/tools/imports), which was updated to reflect changes in recent versions of Go. This is in compliance with the [Go Release Policy](https://golang.org/doc/devel/release.html#policy) respectively the [Go Release Maintenance](https://github.com/golang/go/wiki/Go-Release-Cycle#release-maintenance), which states support for each major release until there are two newer major releases.