Revert "Test 1.16beta1"

This reverts commit 4294fcf.

Author: benbjohnson

Diff for: .github/workflows/test.yml

@@ -6,8 +6,7 @@ jobs:
     steps:
       - uses: actions/setup-go@v2
         with:
-          stable: false
-          go-version: '1.16beta1'
+          go-version: '1.15'
 
       - uses: actions/checkout@v2