title: plotly layout - Y Axis range not working
body: <p>i am trying to create a graph that will show a Scatter of the times i opened my computer. - i am using plotly offline. 
  Y  = time, 
  X  = date.</p>
  
  <p>this works fine, but i can't make the Y axis to show all the hours of the day, but only the range of times that was in the data. </p>
  
  <p>(for example, if i opened my computer only between 13:00-15:00 every day, the range of the Y axis will be from 13:00 to 15:00 only)</p>
  
  <p>i am trying to show all the hours of the day on the Y axis by using the 'range' attribute in the layout, but it still doesn't work for me. </p>
  
  <p>an example of my code:</p>
  
  <pre><code>from plotly.offline import download_plotlyjs, init_notebook_mode, plot, iplot
  from plotly.graph_objs import *
  from datetime import datetime, time
  
  init_notebook_mode(connected=True)
  
  # in the example i am using fabricated data. declaring the data:
  time_data = [datetime(2017, 07, 28, 21, 37, 19), datetime(2017, 07, 29, 17, 11, 56), datetime(2017, 08, 01, 11, 15, 45), datetime(2017, 08, 02, 13, 54, 03)]
  x_data = []
  y_data = []
  
  # creating the x-row data with dates only, and the y-row data with the time only
  for row in time_data:
      x_data.append(row.date())
      y_data.append(datetime.combine(datetime(2017, 1, 1).date(), row.time))
  
  #declaring the data for the graph
  data = [Scatter(x=x_data, y=y_data, name='Times On', mode='markers')]
  
  # creating the hour range 
  hours = []
  for i in range (0, 24):
      hours.append(datetime(2017, 1, 1, i, 0, 0))
  
  # declaring the Layout with the 'range' attribute, and Figure
  layout = dict(title='Times On', xaxis=dict(type='date'), yaxis={'type': 'date', 'tickformat': '%H:%M', 'range': hours})
  fig = Figure(data=data, layout=layout)
  
  # plotting
  plot(figure_or_data=fig, filename='C:\Users\tototo\Desktop\Time-On')
  </code></pre>
  
  <p>does someone know what's the problem? any help would be blessed! 
  Thanks!</p>