Add ubuntu and mac to the 1.16.x build matrix

Author: kishaningithub

.github/workflows/test.yml

@@ -51,6 +51,12 @@ jobs:
           - go-version: 1.15.x
             os: windows-latest
             go-flags: "-trimpath"
+          - go-version: 1.16.x
+            os: ubuntu-latest
+            go-flags: "-trimpath"
+          - go-version: 1.16.x
+            os: macos-latest
+            go-flags: "-trimpath"
           - go-version: 1.16.x
             os: windows-latest
             go-flags: "-trimpath"