add go1.15 to test matrix, dont ignore tls common-names

Author: jpillora

.github/workflows/ci.yml

@@ -10,7 +10,7 @@ jobs:
     name: Test
     strategy:
       matrix:
-        go-version: [1.13.x, 1.14.x]
+        go-version: [1.13.x, 1.14.x, 1.15.x]
         platform: [ubuntu-latest, macos-latest, windows-latest]
     runs-on: ${{ matrix.platform }}
     steps:
@@ -24,6 +24,8 @@ jobs:
         run: go build -v .
       - name: Test
         run: go test -v ./...
+        env:
+          GODEBUG: x509ignoreCN=0
   # ================
   # RELEASE JOB
   #   runs after a success test