Add start of the EC2/S3 API testing to tempest

Continues the effort of the https://review.openstack.org/#/c/3064/

* add EC2 keypair and volume tests
* add EC2 snapshot from volume test
* add EC2 floating ip disasscioation
* add EC2 operation on security group
* add EC2/S3 image registration
* add EC2 instance run test
* add Integration test with ssh, console, volume
* add S3 object and bucket tests

Change-Id: I0dff9b05f215b56456272f22aa1c014cd53b4f4b
diff --git a/tools/pip-requires b/tools/pip-requires
index d3f9db7..9c861d9 100644
--- a/tools/pip-requires
+++ b/tools/pip-requires
@@ -4,3 +4,4 @@
 pika
 unittest2
 lxml
+boto>=2.2.1