Add initial grpc generation, and add to gradle build

SwiftyCar/build.gradle

@@ -0,0 +1,16 @@
+configurations{
+        swift {
+            canBeConsumed = false
+            canBeResolved = true
+    }
+}
+
+dependencies {
+    swift project(path: ':protobuf', configuration: 'swift')
+}
+
+task copySwiftCode(type: Copy, dependsOn: configurations.swift) {
+    // Copy python protobuf code from proto project.
+    from zipTree(configurations.swift.asPath)
+    into './Sources/Generated'
+}