This PR fixes below issues:
1. remove concurrent installation for various versions
We were doing this to decrease the amount of execution time the versions test.
However, it's returning incorrect exit code when there's an
installation failure.
Right now, we are only installing two versions of `storj-sim` and
the rest are only doing uplink cli installation. The performance of
this test should be hugely impacted by the setup step now.
2. only remove release settings instead of deleting the entire file
uplink CLI is referrencing `private/version` package. Therefore, we
cannot delete it
3. add back `GATEWAY_0_API_KEY` in storj-sim
In order to set up older version of uplink cli, we need access to
the gate way api key.
Change-Id: Ia3c37c197bd007b6e1f7c2bd71adde42181d46f0
8fd841b910