Remove vendored dependencies (#455)

.github/workflows/test.yml

@@ -2,30 +2,28 @@ name: Test
 
 on: [push, pull_request]
 
-env:
-  GO111MODULE: on
-
 jobs:
   test:
     strategy:
       fail-fast: false
       matrix:
         platform: [ubuntu-latest, macos-latest, windows-latest]
-        go: ["1.17", "1.16"]
+        go: ["1.19", "1.18", "1.17", "1.16"]
+
     runs-on: ${{ matrix.platform }}
+
     steps:
+    - name: Check out code
+      uses: actions/checkout@v3
+
     - name: Set up Go
-      uses: actions/setup-go@v2
+      uses: actions/setup-go@v3
       with:
         go-version: "${{ matrix.go }}"
-
-    - name: Check out code into the Go module directory
-      uses: actions/checkout@v2
+        cache: true
 
     - name: Add problem matcher
       run: echo "::add-matcher::$PWD/.github/matchers.json"
 
     - name: Run tests
       run: go test -timeout 30s -v $(go list -v ./... | grep -vE '(tests|examples)$')
-      env:
-        GOFLAGS: "-mod=vendor"