Merge pull request #37 from jonboulle/go118

Go 1.18

Author: sagikazarmark

.github/workflows/ci.yaml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        go: ['1.11', '1.12', '1.13', '1.14', '1.15', '1.16', '1.17']
+        go: ['1.11', '1.12', '1.13', '1.14', '1.15', '1.16', '1.17', '1.18']
     env:
       GOFLAGS: -mod=readonly