Support xAPI 1.0.3

[madmox]

ADL released xAPI 1.0.3 on september 21st, 2016. When will TinCan.NET support 1.0.3? Even if it just means updating the supported versions list and the latest/default version used by the client.

[madmox]

See #28

A test on Master is failing because of 1.0.3. This is unfortunate.