fix pip install errors

This patch fixes the following errors when running `IHaskell console`:

* Jinja2 tarball, markupsafe not found

        ... ...
        Downloading/unpacking jinja2==2.7.1
          Real name of requirement jinja2 is Jinja2
        Saved /tmp/tmpThreadId12994/Jinja2-2.7.1.tar.gz
        ... ...
        Successfully downloaded jinja2 markupsafe
        Cleaning up...
        tar (child): jinja2-2.7.1.tar.gz: Cannot open: No such file or directory
        tar (child): Error is not recoverable: exiting now
        /bin/tar: Child returned status 2
        /bin/tar: Error is not recoverable: exiting now
        ... ...
        Couldn't find index page for 'markupsafe' (maybe misspelled?)
        Download error on http://pypi.python.org/simple/: timed out -- Some packages may not be found!
        No local packages or download links found for markupsafe
        error: Could not find suitable distribution for Requirement.parse('markupsafe')

* MarkupSafe already installed as a dependency of Jinja2

        Searching for markupsafe
        Reading http://pypi.python.org/simple/markupsafe/
        Best match: MarkupSafe 0.18
        Downloading https://pypi.python.org/packages/source/M/MarkupSafe/MarkupSafe-0.18.tar.gz#md5=f8d252fd05371e51dec2fe9a36890687
        Processing MarkupSafe-0.18.tar.gz
        Running MarkupSafe-0.18/setup.py -q bdist_egg --dist-dir /tmp/easy_install-3rw7g1/MarkupSafe-0.18/egg-dist-tmp-XTNM3D
        Adding MarkupSafe 0.18 to easy-install.pth file
        
        Installed /admin/.ihaskell/ipython/lib/python2.7/site-packages/MarkupSafe-0.18-py2.7-linux-x86_64.egg
        Finished processing dependencies for Jinja2==2.7.1
        Installing dependency: MarkupSafe-0.18
        Downloading/unpacking MarkupSafe==0.18
          Downloading MarkupSafe-0.18.tar.gz
        The file /tmp/tmpThreadId16407/MarkupSafe-0.18.tar.gz exists. (i)gnore, (w)ipe, (b)ackup Exception:
        Traceback (most recent call last):
          File "/usr/lib/python2.7/dist-packages/pip/basecommand.py", line 104, in main