Use the new build env on Travis

faster better stronger

(runs on EC2 using LXC and Docker)
Merge branch 'release-1.6.3' into develop

* release-1.6.3:
  Bumping version to 1.6.3
  Update integration test
  Update changelog
Register timestamp parser after profile is set

The issue was that setting a profile for a session resets all
the registered components for the session, including the
response parser that alters the timetsamp parsing behavior in the
AWS CLI.

To fix this, I've added a new event that I think will be useful
in general, a `session-initialized` event, sent once the session
has its profile set.  There are actually several handlers that
I think should switch over to this signal, which I'll add in
a separate pull request.

I've also added an integration test to ensure we don't regress
on this issue again.
Merge branch 'joshk-patch-1' into develop

* joshk-patch-1:
  Use the new build env on Travis
Merge branch 'datetime-fix' into develop

* datetime-fix:
  Register timestamp parser after profile is set
Switch assumerole over to session-initialized event

This also meant that because the scalarparse is hooked into
this event, it always needs to be registered first.
Merge branch 'assume-role-fix' into develop

* assume-role-fix:
  Switch assumerole over to session-initialized event
Add assumerole issue to changelog
Fix failing integ test

Need to copy existing env vars and inject the aws config
file override.
Bumping version to 1.6.4
Merge branch 'release-1.6.4'

* release-1.6.4:
  Bumping version to 1.6.4
  Fix failing integ test
  Add assumerole issue to changelog
  Switch assumerole over to session-initialized event
  Register timestamp parser after profile is set
  Use the new build env on Travis