Add 'environment' package

This commit adds a new environment package that manages all calls to the
underlying operating system.

pkg/environment/native_net.go

@@ -0,0 +1,11 @@
+package environment
+
+import "net"
+
+func (Native) Listen(network, address string) (net.Listener, error) {
+	return net.Listen(network, address)
+}
+
+func (Native) Dial(network, address string) (net.Conn, error) {
+	return net.Dial(network, address)
+}