Skip container function with uri defined

It looks like a container function defined with a `uri` shouldn't be handled by the plugin because the image won't be handled by Serverless itself.
So we just skip the function in that case.

lib/utils.js

@@ -110,8 +110,15 @@ function splitLines(str) {
 
 function getAllNodeFunctions() {
   const functions = this.serverless.service.getAllFunctions();
+
   return _.filter(functions, funcName => {
     const func = this.serverless.service.getFunction(funcName);
+
+    // if `uri` is provided, it means the image isn't built by Serverless so we shouldn't take care of it
+    if (func.image && func.image.uri) {
+      return false;
+    }
+
     const runtime = func.runtime || this.serverless.service.provider.runtime || 'nodejs';
     return runtime.match(/node/);
   });

tests/validate.test.js

@@ -507,7 +507,7 @@ describe('validate', () => {
         },
         dockerfunc: {
           image: {
-            name: 'some-image-uri',
+            name: 'some-docker-image',
             command: ['com.serverless.Handler']
           },
           events: [
@@ -518,6 +518,21 @@ describe('validate', () => {
               }
             }
           ]
+        },
+        dockerfuncuri: {
+          image: {
+            name: 'some-image-with-uri',
+            uri: 'http://hub.dock.er/image',
+            command: ['method.lambda']
+          },
+          events: [
+            {
+              http: {
+                method: 'POST',
+                path: 'mydockerfuncpath'
+              }
+            }
+          ]
         }
       };