add some sleep timers to hopefully fix the travis failures

features/step_definitions/dependencies_steps.rb

@@ -14,6 +14,7 @@ When /^I drag "(.*)" to "(.*)"$/ do |dragged, target|
   drop_elem = page.find(:xpath, "//div[@id='line_todo_#{drop_id}']")
 
   drag_elem.drag_to(drop_elem)
+  sleep 0.2 # wait for the resulting events to be handled in the browser
 end
 
 When /^I expand the dependencies of "([^\"]*)"$/ do |todo_name|

features/support/tracks_step_helper.rb

@@ -121,6 +121,7 @@ module TracksStepHelper
     expect(page).to have_css(submenu_arrow, :visible=>true)
     arrow = page.find(submenu_arrow, :match => :first)
     arrow.click
+    sleep 0.2 # wait for the event to be handled by the browser
     
     submenu_css = "div#line_todo_#{todo.id} ul#ultodo_#{todo.id}"
     submenu = page.find(submenu_css)