Make ftests fail if Juju env is not ready.

Make ftests fail if Juju env is not ready.

The functional tests are no longer silently skipped
if the default Juju environment cannot be found.

Also fail if the environment is running, as this
would cause it to be destroyed at the end of the
suite.

QA:
- bootstrap your default environment;
- run `make ftest`/`make fcheck` and ensure
  the functional tests fail 
  (environment already bootstrapped);
- destroy your environment;
- run `make fcheck` again and ensure all the
  suites complete successfully.

https://code.launchpad.net/~frankban/juju-quickstart/ftest-fixes/+merge/248755

(do not edit description out of merge proposal)

[frankban, 2015-02-05 13:37:38]

Please take a look.

[jeff.pihach, 2015-02-05 15:34:28]

LGTM Thanks for this follow-up!

[kadams54, 2015-02-05 16:06:18]

LGTM as well.

[frankban, 2015-02-05 16:35:07]

*** Submitted:

Make ftests fail if Juju env is not ready.

The functional tests are no longer silently skipped
if the default Juju environment cannot be found.

Also fail if the environment is running, as this
would cause it to be destroyed at the end of the
suite.

QA:
- bootstrap your default environment;
- run `make ftest`/`make fcheck` and ensure
  the functional tests fail 
  (environment already bootstrapped);
- destroy your environment;
- run `make fcheck` again and ensure all the
  suites complete successfully.

R=jeff.pihach, kadams54
CC=
https://codereview.appspot.com/195690043

[frankban, 2015-02-05 16:35:39]

Thanks for the reviews!