'**SUMMARY**
This method returns the length of the line.
**RETURNS**
A floating point length value.
**EXAMPLE**
>>> img = Image("OWS.jpg")
>>> lines = img.findLines
>>> for l in lines:
>>>    if l.length() > 100:
>>>       print "OH MY! - WHAT A BIG LINE YOU HAVE!"
>>>       print "---I bet you say that to all the lines."'

def length(self):

    return float(spsd.euclidean(self.end_points[0], self.end_points[1]))
