Rename settings_oslo parameter MANAGER to ENV_MANAGER

ENV_MANAGER variable will be used to activate one of
the environment managers:
ENV_MANAGER=devops - create, power on/off VM and BM nodes,
                     snapshots for libvirt VMs
ENV_MANAGER=heat   - create OpenStack heat stack
ENV_MANAGER=empty  - only for SSH to an existing environment

Change-Id: I90a59107a7fd350ecfeb821734c2dac4e351d468
diff --git a/tcp_tests/settings_oslo.py b/tcp_tests/settings_oslo.py
index 5717875..e930729 100644
--- a/tcp_tests/settings_oslo.py
+++ b/tcp_tests/settings_oslo.py
@@ -86,8 +86,8 @@
 _default_cluster_maas_config = 'cluster_infra_maas.yml'
 
 hardware_opts = [
-    ct.Cfg('manager', ct.String(),
-           help="Hardware manager name", default="devops"),
+    ct.Cfg('env_manager', ct.String(),
+           help="Hardware environment manager name", default="devops"),
     ct.Cfg('conf_path', ct.String(),
            help="Hardware config file", default=_default_conf),
     ct.Cfg('current_snapshot', ct.String(),