Add uppercase env var names for consistency

Some env var names (the vars starting with manilaclient_) are mixing
lower and uppercase. To be consistent with the other env vars (and
also with env vars from other openstack client projects), add also
the only-upper-case var names. Newly added env variables are:

- MANILACLIENT_UUID_CACHE_DIR
- MANILACLIENT_DEBUG
- MANILACLIENT_INSECURE

Closes-bug: #1535284
Change-Id: Ifd43c6d226487d2b1c4ec099096595373725e596

manilaclient/base.py

@@ -90,6 +90,7 @@ class Manager(utils.HookableMixin):
         often enough to keep the cache reasonably up-to-date.
         """
         base_dir = cliutils.env('manilaclient_UUID_CACHE_DIR',
+                                'MANILACLIENT_UUID_CACHE_DIR',
                                 default="~/.manilaclient")
 
         # NOTE(sirp): Keep separate UUID caches for each username + endpoint

manilaclient/shell.py

@@ -128,6 +128,7 @@ class OpenStackManilaShell(object):
         parser.add_argument('-d', '--debug',
                             action='store_true',
                             default=cliutils.env('manilaclient_DEBUG',
+                                                 'MANILACLIENT_DEBUG',
                                                  default=False),
                             help="Print debugging output.")
 
@@ -296,6 +297,7 @@ class OpenStackManilaShell(object):
 
         parser.add_argument('--insecure',
                             default=cliutils.env('manilaclient_INSECURE',
+                                                 'MANILACLIENT_INSECURE',
                                                  default=False),
                             action='store_true',
                             help=argparse.SUPPRESS)