Update Application media type version for v1.3 release

Set the version to v3 for Application media type since that is
the newest version introduced in v1.3.

Fixes: MN-1098

Signed-off-by: Ryu Ishimoto <ryu@midokura.com>
Merge pull request #92 from ryu25ish/v1.3_api_version_upgrade

Update Application media type version for v1.3 release