def is_increasing_trend(self):
        """Returns True if the past three values have been strictly
        increasing

        Returns False if there have been less than three updates so far

        >>> stock = Stock("GOOG")
        >>> stock.is_increasing_trend()
        False
        """

        return self.history[-3].value < \
            self.history[-2].value < self.history[-1].value

Failed example:
    stock.is_increasing_trend()
Exception raised:
    Traceback (most recent call last):
      File "C:\Python34\lib\doctest.py", line 1324, in __run
        compileflags, 1), test.globs)
      File "<doctest __main__.Stock.is_increasing_trend[1]>", line 1, in <module>
        stock.is_increasing_trend()
      File "c:\Projects\tdd_with_python\src\stock_alerter\stock.py", line...