fixed some sphinx warnings in release docs

Re #0

docs/source/release/v3.14.0/index.rst

-.. _v3.13.0:
+.. _v3.14.0:
 
 ===========================
-Mantid 3.13.0 Release Notes
+Mantid 3.14.0 Release Notes
 ===========================
 
 .. contents:: Table of Contents
    :local:
 
 
-We are proud to announce version 3.13.0 of Mantid.
+We are proud to announce version 3.14.0 of Mantid.
 
 Here is a load of stuff we have done.
 
@@ -17,7 +17,7 @@ Citation
 
 Please cite any usage of Mantid as follows: **TODO update with current version doi**
 
-- *Mantid 3.13.0: Manipulation and Analysis Toolkit for Instrument Data.; Mantid Project*. `doi: 10.5286/SOFTWARE/MANTID3.13.0 <http://dx.doi.org/10.5286/SOFTWARE/MANTID3.13.0>`_
+- *Mantid 3.14.0: Manipulation and Analysis Toolkit for Instrument Data.; Mantid Project*. `doi: 10.5286/SOFTWARE/MANTID3.14.0 <http://dx.doi.org/10.5286/SOFTWARE/MANTID3.14.0>`_
 
 - Arnold, O. et al. *Mantid-Data Analysis and Visualization Package for Neutron Scattering and mu-SR Experiments.* Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 764 (2014): 156-166 `doi: 10.1016/j.nima.2014.07.029 <https://doi.org/10.1016/j.nima.2014.07.029>`_ (`download bibtex <https://raw.githubusercontent.com/mantidproject/mantid/master/docs/source/mantid.bib>`_)
 
@@ -46,6 +46,6 @@ For a full list of all issues addressed during this release please see the `GitH
 
 .. _forum: http://forum.mantidproject.org
 
-.. _GitHub milestone: http://github.com/mantidproject/mantid/pulls?utf8=%E2%9C%93&q=is%3Apr+milestone%3A"Release+3.13"+is%3Amerged
+.. _GitHub milestone: http://github.com/mantidproject/mantid/pulls?utf8=%E2%9C%93&q=is%3Apr+milestone%3A"Release+3.14"+is%3Amerged
 
-.. _GitHub release page: https://github.com/mantidproject/mantid/releases/tag/v3.13.0
+.. _GitHub release page: https://github.com/mantidproject/mantid/releases/tag/v3.14.0