Fix envvar subsitution in config files

PyYaml 5.1 regression doesnt resolve envvars in configuration files
Fix bz 1688647

This isn't a bug fix per se, as rhel image was never affected.
Rhel image uses pyyaml 3.10.
Only centos image was affected, because python deps are installed
via pip.

curator/Dockerfile.centos7

@@ -25,7 +25,7 @@ RUN yum install -y epel-release && \
     rpm --import https://packages.elastic.co/GPG-KEY-elasticsearch
 RUN yum install -y --setopt=tsflags=nodocs \
         python-pip && \
-    pip install --no-cache-dir 'ruamel.yaml<=0.15' elasticsearch-curator==${CURATOR_VER} && \
+    pip install --no-cache-dir 'pyyaml==3.12' 'ruamel.yaml<=0.15' elasticsearch-curator==${CURATOR_VER} && \
     yum clean all
 
 COPY run.sh lib/oalconverter/* ${HOME}/

curator/README.md

@@ -99,9 +99,6 @@ months from that date.
 If you want to be exact with curator, it is best to use `days` e.g. `delete: days: 31`
 [Curator issue](https://github.com/elastic/curator/issues/569)
 
-### Compatibility with OpenShift 3.7
-In earlier releases admins could control the timezone and time when curator runs from the curator config. This configuration has been moved to openshift-ansible. The [timezone is not currently configurable](https://github.com/kubernetes/kubernetes/issues/47202), instead the timezone of OpenShift master node is used.
-
 ### Using actions file
 OpenShift custom config file format ensures that important internal indices don't get deleted by mistake. In order to use the actions file add an [exclude](https://www.elastic.co/guide/en/elasticsearch/client/curator/5.2/fe_exclude.html) rule to your configuration to retain these indices. You also need to manually add all the other patterns, see action 3 in the below example:
 ```
@@ -209,3 +206,14 @@ oc patch cronjob logging-curator -p '{"spec":{"schedule":"0 0 * * *"}}'
 # this
 oc create job --from=cronjob/logging-curator <job_name>
 ```
+
+#### Hacking on oalconverter
+Create virtual environment
+```
+virtualenv dev
+source dev/bin/activate
+```
+Edit `.py` files and run tests
+```
+python setup.py test
+```