Change VTN Manager version to 0.2.0 for Helium release.

Succeeding patches will change VTN Manager API. So I decided to change
VTN Manager version in advance.

Change-Id: I0d580002ed1c773d01468d9eb6a4d0006d64539e
Signed-off-by: Shigeru Yasuda <s-yasuda@da.jp.nec.com>