explicitly specify executor to be bash for tests

We use prove command to run tests. Sometimes tests fail rather strangely
with error as shown below:

Not a perl script at ./tests/bugs/core/bug-1111557.t line 1.
./tests/bugs/core/bug-1111557.t ..
Dubious, test returned 25 (wstat 6400, 0x1900)
No subtests run

https://build.gluster.org/job/centos6-regression/3818/consoleFull
https://build.gluster.org/job/centos6-regression/3819/consoleFull
https://build.gluster.org/job/centos6-regression/3801/consoleFull

Quote from man page

``
 "--exec"
       Normally you can just pass a list of Perl tests and the harness
will know how to execute them.  However, if your tests are not written in Perl
or if you want all tests invoked exactly the same way, use the "-e",
or "--exec" switch:

        prove --exec '/usr/bin/ruby -w' t/
```

Hence, better to comply with recommended practice although it might not
be the reason for this failure.

Change-Id: If7a0baf20698f8497ef3e8fc422fa67063a4651f
BUG: 1438858
Signed-off-by: Raghavendra Talur <rtalur@redhat.com>
Reviewed-on: https://review.gluster.org/16996
Smoke: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: N Balachandran <nbalacha@redhat.com>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
Reviewed-by: Nigel Babu <nigelb@redhat.com>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Jeff Darcy <jeff@pl.atyp.us>

0 files changed, 0 insertions, 0 deletions