Update Istio app version

Changelog for 0.1.7:

• PR #26 bumped istio to 1.4.5 according to the docs to fix issue #25 by @aidun

Commits
bb980d5 Fixes #25: updated istio to version 1.4.5 by @aidun
d2934b5 Add t-shirt link by @alexellis

Generated by Derek