Update golang version in CI.

Author: arijitAD

.github/workflows/checks.yml

@@ -6,6 +6,9 @@ jobs:
   linter-check:
     runs-on: ubuntu-latest
     steps:
+      - uses: actions/setup-go@v2
+        with:
+          go-version: '1.16.x'
       - uses: actions/checkout@v2
       - name: Run linter
         run:  go run build/ci.go lint

.github/workflows/on-pr.yml

@@ -15,7 +15,7 @@ jobs:
     name: Run geth unit test
     strategy:
       matrix:
-        go-version: [ 1.15.x]
+        go-version: [ 1.16.x]
         platform: [ubuntu-latest]
     runs-on: ${{ matrix.platform }}
     env:
@@ -43,7 +43,7 @@ jobs:
       GOPATH: /tmp/go
     strategy:
       matrix:
-        go-version: [ 1.15.x]
+        go-version: [ 1.16.x]
         platform: [ubuntu-latest]
     runs-on: ${{ matrix.platform }}
     steps: