Move CgRPC, gRPC, and QuickProto to "Sources" directory and add new top-level Package.swift.

Author: timburks

.gitmodules

@@ -1,6 +0,0 @@
-[submodule "third_party/grpc"]
-	path = third_party/grpc
-	url = https://github.com/grpc/grpc
-[submodule "third_party/swift-protobuf"]
-	path = third_party/swift-protobuf
-	url = https://github.com/apple/swift-protobuf

Packages/CgRPC/Package.swift renamed to Package.swift

@@ -33,5 +33,10 @@
 import PackageDescription
 
 let package = Package(
-    name: "CgRPC"
+  name: "SwiftGRPC",
+  targets: [
+    Target(name: "gRPC",
+           dependencies: ["CgRPC"]),
+    Target(name: "QuickProto"),
+  ]
 )