Use the Provisioner interface for session provisioning (#3)

* fix(route53): Use the Provisioner interface for session provisioning

* chore(route53): Code simplification

route53.go

@@ -21,17 +21,17 @@ func (Provider) CaddyModule() caddy.ModuleInfo {
 	return caddy.ModuleInfo{
 		ID: "dns.providers.route53",
 		New: func() caddy.Module {
-			p := &Provider{new(route53.Provider)}
-			// Initialize the AWS client session
-			err := p.NewSession()
-			if err != nil {
-				return nil
-			}
-			return p
+			return &Provider{new(route53.Provider)}
 		},
 	}
 }
 
+// Provision implements the Provisioner interface to initialize the AWS Client sessions
+func (p *Provider) Provision(ctx caddy.Context) error {
+	// Initialize the AWS client session
+	return p.NewSession()
+}
+
 // UnmarshalCaddyfile sets up the DNS provider from Caddyfile tokens. Syntax:
 //
 // route53 {