Fix errcheck lint and add doctor to help golden file

Author: simonfaltum

acceptance/help/output.txt

@@ -157,6 +157,7 @@ Postgres
 
 Developer Tools
   bundle                                 Declarative Automation Bundles let you express data/AI/analytics projects as code.
+  doctor                                 Validate your Databricks CLI setup
   sync                                   Synchronize a local directory to a workspace directory
 
 Additional Commands:

cmd/doctor/checks.go

@@ -268,7 +268,7 @@ func checkNetworkWithHost(cmd *cobra.Command, host string) CheckResult {
 		}
 	}
 	defer resp.Body.Close()
-	io.Copy(io.Discard, resp.Body)
+	_, _ = io.Copy(io.Discard, resp.Body)
 
 	return CheckResult{
 		Name:    "Network",

cmd/doctor/doctor_test.go

@@ -234,7 +234,7 @@ func TestCheckIdentitySuccess(t *testing.T) {
 	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		if r.URL.Path == "/api/2.0/preview/scim/v2/Me" {
 			w.Header().Set("Content-Type", "application/json")
-			w.Write([]byte(`{"userName": "test@example.com"}`))
+			_, _ = w.Write([]byte(`{"userName": "test@example.com"}`))
 			return
 		}
 		w.WriteHeader(http.StatusOK)
@@ -446,6 +446,6 @@ func TestNewCommandJSONTrailingNewline(t *testing.T) {
 
 	err := cmd.Execute()
 	require.NoError(t, err)
-	assert.True(t, buf.Len() > 0)
+	assert.Positive(t, buf.Len())
 	assert.Equal(t, byte('\n'), buf.Bytes()[buf.Len()-1])
 }