DOC use Python3 compatible print syntax in install docs

doc/install.txt

@@ -745,7 +745,7 @@ Theano dependencies is easy, but be aware that it will take a long time
 
 - Afterwards, please check that the ``scipy`` module that is imported in
   Python is the right one (and is a recent one). For instance, ``import
-  scipy`` followed by ``print scipy.__version__`` and ``print scipy.__path__``
+  scipy`` followed by ``print(scipy.__version__)`` and ``print(scipy.__path__)``
   should result in a version number of at least 0.7.0 and a path that starts
   with ``/opt/local`` (the path where MacPorts installs its packages). If this
   is not the case, then you might have some old installation of ``scipy`` in your

doc/install_ubuntu.txt

@@ -136,7 +136,7 @@ Theano/BLAS speed test:
 
 .. code-block:: bash
 
-    python `python -c "import os, theano; print os.path.dirname(theano.__file__)"`/misc/check_blas.py
+    python `python -c "import os, theano; print(os.path.dirname(theano.__file__))"`/misc/check_blas.py
 
 This will print a table with different versions of BLAS/numbers of
 threads on multiple CPUs and GPUs. It will also print some Theano/NumPy