Bump golang to 1.18.1

Also update all use of 'go get' => 'go install', update CI tooling for
1.18 compatibility, and gofmt everything so lint passes.

Signed-off-by: Brad Davidson <brad.davidson@rancher.com>

.github/workflows/integration.yaml

@@ -47,7 +47,7 @@ jobs:
     - name: Install Go
       uses: actions/setup-go@v2 
       with: 
-        go-version: '1.17.5'
+        go-version: '1.18.1'
     - name: Checkout
       uses: actions/checkout@v2
       with:

.github/workflows/unitcoverage.yaml

@@ -33,7 +33,7 @@ jobs:
     - name: Install Go
       uses: actions/setup-go@v2 
       with: 
-        go-version: '1.17.5'
+        go-version: '1.18.1'
     - name: Checkout
       uses: actions/checkout@v2
       with: