Refactor HTTPBlobImpl to use bosh-utils httpclient
Refactor HTTPBlobImpl to use bosh-utils httpclient

[#167583145](https://www.pivotaltracker.com/story/show/167583145)

Co-authored-by: Joshua Aresty <18e47c05d12d69c65baf02b69e877c81d203331d@emc.com>

cloudfoundry/bosh-agent,gu-bin/bosh-agent,gu-bin/bosh-agent,gu-bin/bosh-agent,cloudfoundry/bosh-agent