fix: load invocationMode from manifest (#458)

Author: eduardoboucas

go/porcelain/deploy_test.go

@@ -449,7 +449,7 @@ func TestBundleWithManifest(t *testing.T) {
 				"runtime": "some-other-runtime",
 				"mainFile": "/some/path/hello-py-function-test",
 				"name": "hello-py-function-test",
-				"invocation_mode": "stream"
+				"invocationMode": "stream"
 			}
 		],
 		"version": 1

go/porcelain/functions_manifest.go

@@ -15,5 +15,5 @@ type functionsManifestEntry struct {
 	Schedule       string `json:"schedule"`
 	DisplayName    string `json:"displayName"`
 	Generator      string `json:"generator"`
-	InvocationMode string `json:"invocation_mode"`
+	InvocationMode string `json:"invocationMode"`
 }