Bump versions of linux headers in trusty OS image test

Signed-off-by: Maria Shaldibina <mshaldibina@pivotal.io>
Update bosh-agent

This includes a cherry-pick of a807749, which is an update to a timebomb
test.

Signed-off-by: Maria Shaldibina <mshaldibina@pivotal.io>
fixes for the gocd usage instructions
can't chown a vagrant mounted dir
Merge branch 'master' of https://github.com/cloudfoundry/bosh into develop
Convert openstack image to qcow2 0.10 compat

Signed-off-by: Maria Shaldibina <mshaldibina@pivotal.io>
Signed-off-by: Kris Hicks <krishicks@gmail.com>
Make instance type configurable in Openstack BATs

via BOSH_OPENSTACK_FLAVOR

Signed-off-by: Kris Hicks <krishicks@gmail.com>
Revert "Add os_image_s3_version to build and publish cmd"

This reverts commit 0e69492dc22b031a1656ded8092fc7c6ada30408.
Revert "Add os_image_s3_version to publish_stemcell_in_vm"

This reverts commit 2b493770b97e917144307f14cc7dff3e094a85a1.
Revert "Add and require os_image_version for stemcell:build"

This reverts commit 02d7e67cd7de4aa07ecd8c374a84cbda982c29db.
Lock down os_image_version in code

Signed-off-by: Kris Hicks <krishicks@gmail.com>
Update OS_IMAGES.md

Signed-off-by: Kris Hicks <krishicks@gmail.com>
Set net_id only if BOSH_OPENSTACK_NET_ID present

Signed-off-by: Kris Hicks <krishicks@gmail.com>
Merge branch '2719.2' into develop

Signed-off-by: Kris Hicks <krishicks@gmail.com>

Conflicts:
	go/src/github.com/cloudfoundry/bosh-agent
	stemcell_builder/stages/image_openstack_qcow2/apply.sh
Update trusty OS image
Switch m1.small to m1.medium in bosh_cli_plugin_aws
Update BATs to use m1.medium
Only set net_id if specified in BATs
Configure flavor without ephemeral disk

via BOSH_OPENSTACK_FLAVOR_WITH_NO_EPHEMERAL_DISK

Signed-off-by: Maria Shaldibina <mshaldibina@pivotal.io>
Add workstation setup to Contributing.md

Running `bundle` leads to some cases where gems can't be installed due to missing dependencies for their native extensions. Specifically installing the pg gem proves more difficult than necessary if you install postgresql using brew, as it does't fix the architecture to `x86_64`. Furthermore, redis and golang are needed for running the tests with `bundle exec rake`.