TTV 1.0.0 Alpha 3 Release

An updated alpha 3 release of TTV is available at [1], with prebuilt
binary and source artifacts at [2].

This update fixes the following issues:

 * Issue #24 <https://github.com/skynav/ttv/issues/24> - Unable to
resolve relative URI on Windows platform

 * Issue #26 <https://github.com/skynav/ttv/issues/26> - Add support
for SMPTE-TT verification models

 * Issue #27 <https://github.com/skynav/ttv/issues/27> - Add support
external schemas via --external-schema option.

 * Issue #28 <https://github.com/skynav/ttv/issues/28> - Add support
for showing platform validator information via --show-validator
option.

[1] https://github.com/skynav/ttv/tree/ttv-1.0.0a3
[2] https://github.com/skynav/ttv/tree/ttv-1.0.0a3/dst