Fix path to tarball release
Fix path to tarball release

The e2e tests were failing because the tarball release could
not be found at the path specified. This commit fixes the path.

[#104248646](https://www.pivotaltracker.com/story/show/104248646)

Signed-off-by: Edwin Xie <6bc24e9c160281972837d9e13287696d26612564@pivotal.io>

cloudfoundry-incubator/bosh-aws-cpi-release,cloudfoundry-incubator/bosh-aws-cpi-release,cloudfoundry-incubator/bosh-aws-cpi-release