Blacklist babel==2.4.0 in test-requirements

Sphinx wants babel!=2.0,>=1.3 which drags in 2.4.0, but oslo.i18n
(required by keystone) wants Babel!=2.4.0,>=2.3.4 leading to an
error when starting keystone.

Also, bump up the sleep before verifying that keystone is running
-- at just one second, keystone hadn't had a chance to raise the
ContextualVersionConflict yet. Further, verify that curl can actually
reach keystone on the expected port.

Change-Id: I6cbbfd7260571f42ea65c6622aa6b410a0e43b28

swift3/test/functional/setup_keystone

@@ -93,8 +93,9 @@ _setup_keystone()
         > "${log_file}" 2>&1 &
     export keystone_pid=$!
     # make sure it's actually running
-    sleep 1
+    sleep 5
     ps -p $keystone_pid
+    curl -I $OS_AUTH_URL
 
     _create_swift_accounts
 }

test-requirements.txt

@@ -11,3 +11,4 @@ requests!=2.12.2,!=2.13.0
 requests-mock>=0.7.0 # Apache-2.0
 fixtures<2.0,>=1.3.1 # Apache-2.0/BSD
 keystonemiddleware
+babel!=2.4.0