Run tests on go18 due fuzz tests

Author: bzick

.github/workflows/tokenizer.yml

@@ -12,7 +12,7 @@ jobs:
     steps:
       - uses: actions/setup-go@v3
         with:
-          go-version: '1.17'
+          go-version: '1.18'
 
       - uses: actions/checkout@v3
 
@@ -28,7 +28,7 @@ jobs:
 
       - uses: actions/setup-go@v3
         with: 
-          go-version: 1.17.x
+          go-version: 1.18.x
 
       - name: Run tests
         run: go test -race -coverprofile=coverage.txt -covermode=atomic ./...