Dayplot error when giving the events argument

I am giving the events argument to generate the dayplot with events labeled on the plot, but it gave me the following error, looking into the waveform.py, it seems this check should be checked when the code automatically download the Catalog object (when using events={"min_magnitude": 5.5}) instead of manually giving the time of the events. 

```python
st.plot(type = 'dayplot', events=[{"time": UTCDateTime("2014-03-29T04:09:42"), "text": "M 5.1"}])
```

```python
/Library/Python/2.7/site-packages/obspy/imaging/waveform.pyc in _plotEvent(self, event)
    573                 markersize=12, linewidth=self.linewidth)
    574 
--> 575         for pick in event.picks:
    576             # check that network/station/location matches
    577             if pick.waveform_id.getSEEDString().split(".")[:-1] != \

AttributeError: 'dict' object has no attribute 'picks'
```