Make cargo packaging explicit

Author: pfmooney

Diff for: Cargo.toml

@@ -10,6 +10,13 @@ documentation = "https://docs.rs/net2/~0.2"
 description = """
 Extensions to the standard library's networking types as proposed in RFC 1158.
 """
+include = [
+  "Cargo.toml",
+  "LICENSE-APACHE",
+  "LICENSE-MIT",
+  "README.md",
+  "src/**/*.rs"
+]
 
 [target."cfg(windows)".dependencies]
 winapi = { version = "0.3", features = ["handleapi", "winsock2", "ws2def", "ws2ipdef", "ws2tcpip"] }