start to implementig clone to create namespaces

src/namespace/consts.rs

@@ -0,0 +1,3 @@
+pub const NET_NS_DIR:&str = "/var/run/netns";
+pub const PROC_NS_DIR:&str = "/proc/self/ns/net";
+pub const STACK_SIZE: usize = 1024 * 1024;