Upgrade Go to 1.18

Author: elgopher

.github/workflows/build.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-20.04
     strategy:
       matrix:
-        go: [ 1.17 ]
+        go: [ 1.17, 1.18 ]
     steps:
       - uses: actions/checkout@v2
 
@@ -35,7 +35,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v2
         with:
-          go-version: 1.17
+          go-version: 1.18
 
       - name: Test
         run: go test -v -coverprofile=coverage.txt -covermode=atomic ./...

go.mod

@@ -1,6 +1,6 @@
 module github.com/elgopher/mapify
 
-go 1.17
+go 1.18
 
 require github.com/stretchr/testify v1.7.0