0.4rc1: DocTestFailure on  docs/time/index.rst

On Debian/Powerpc and Debian/s390x, the 0.4rc1 version fails with
```
619 :meth:`~astropy.time.Time.sidereal_time`.  [...]
625   >>> t = Time('2006-01-15 21:24:37.5', scale='utc', location=('120d', '45d'))
626   >>> t.sidereal_time('mean')
627   <Longitude 13.089521870640... hourangle>
628   >>> t.sidereal_time('apparent')
Expected:
    <Longitude 13.089503675087... hourangle>
Got:
    <Longitude 13.089503675086998 hourangle>
```
* [powerpc build log](https://buildd.debian.org/status/fetch.php?pkg=python-astropy&arch=powerpc&ver=0.4~rc1-1&stamp=1404749162)
* [s390x build log](https://buildd.debian.org/status/fetch.php?pkg=python-astropy&arch=s390x&ver=0.4~rc1-1&stamp=1404755898)