Crash dump checks don't work on RedHat Linux

[Koji Nakazono]

Crash dump checks count the number of directories which is date format.
https://github.com/stackforge/monasca-agent/blob/master/monasca_agent/collector/checks_d/crash.py#L30
dt = datetime.strptime(entry, '%Y%m%d%H%M')

However, the directory name format for crash dump on RedHat OS is below.
<IP address>-<date>
e.g. 127.0.0.1-2015.09.28-20:50:02

So crash dump checks cannot count the directories on RedHat OS environment.
However, crash dump checks automatically become enabled on RedHat OS if crash dump is enabled on it.

I think that it's good to support RedHat OS crash dump.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/230309

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/230309
Committed: https://git.openstack.org/cgit/openstack/monasca-agent/commit/?id=587d202f1da71b73162672c2cb7efcc413c64f61
Submitter: Jenkins
Branch: master

commit 587d202f1da71b73162672c2cb7efcc413c64f61
Author: Koji Nakazono <email address hidden>
Date: Mon Oct 19 21:09:55 2015 +0900

    Support the format of crash dump directory for RHEL7.1 and CentOS7.1

    Currently, crash checks support only below format.
    YYYYMMddHHmm (e.g. 201509032311)
    Support the format of RHEL7.1 and CentOS7.1.
    <IP-address>-YYYY.MM.dd-HH:mm:ss (e.g. 127.0.0.1-2015.10.02-16:07:51)

    Change-Id: Ia023edc3505e584200b043814480bfcfbd60920c
    Closes-Bug: #1500766