RELEASE: update version numbers in getting_started.rst

Following instructions in doc/release-howto.rst

Author: ariddell

doc/getting_started.rst

@@ -42,10 +42,10 @@ dependencies, then issue the commands:
 
 ::
 
-   wget https://pypi.python.org/packages/source/p/pystan/pystan-2.12.0.0.tar.gz
+   wget https://pypi.python.org/packages/source/p/pystan/pystan-2.14.0.0.tar.gz
    # alternatively, use curl, or a web browser
-   tar zxvf pystan-2.12.0.0.tar.gz
-   cd pystan-2.12.0.0
+   tar zxvf pystan-2.14.0.0.tar.gz
+   cd pystan-2.14.0.0
    python setup.py install
    cd ..  # change out of the source directory before importing pystan