Added apis to scenario manager

Tempest plugins do use associate_floating_ip() and
disassociate_floating_ip() api but scenario-
manager doesn't implement it.
The plugins using these apis are manila-tempest-
plugin, tap, vmware-nsx and neutron-tempest-plugin.
Hence, added it to the scenario manager

Implements: blueprint tempest-scenario-manager-stable
Signed-off by: Soniya Vyas<svyas@redhat.com>
Change-Id: I41792bdc3478f5f290a6b3b7172ef3f6b4c62c19
diff --git a/releasenotes/notes/associate-disassociate-floating_ip-0b6cfebeef1304b0.yaml b/releasenotes/notes/associate-disassociate-floating_ip-0b6cfebeef1304b0.yaml
new file mode 100644
index 0000000..8e42e85
--- /dev/null
+++ b/releasenotes/notes/associate-disassociate-floating_ip-0b6cfebeef1304b0.yaml
@@ -0,0 +1,5 @@
+---
+features:
+  - |
+    Added associate_floating_ip() and dissociate_floating_ip() methods
+    to the scenario manager.