Add license in swift code file
Add license in swift code file

Source code should be licensed under the Apache 2.0 license.
Add Apache License in swift/probe/__init__.py file.

Change-Id: I3b6bc2ec5fe5caac87ee23f637dbcc7a5d8fc331

smerritt/swift,notmyname/swift,smerritt/swift,tipabu/swift,clayg/swift,tipabu/swift,nadeemsyed/swift,swiftstack/swift,clayg/swift,openstack/swift,psachin/swift,notmyname/swift,psachin/swift,clayg/swift,nadeemsyed/swift,smerritt/swift,tipabu/swift,openstack/swift,matthewoliver/swift,tipabu/swift,openstack/swift,swiftstack/swift,clayg/swift,openstack/swift,nadeemsyed/swift,matthewoliver/swift,psachin/swift,smerritt/swift,matthewoliver/swift,psachin/swift,nadeemsyed/swift,notmyname/swift,swiftstack/swift,notmyname/swift,matthewoliver/swift