Merge pull request #948 from alphagov/test-driven-development

BAU: Test-driven development

source/partials/_nav-software-development.html.erb

@@ -5,6 +5,7 @@
   <li><a href="/standards/tracking-dependencies.html">How to manage third party software dependencies</a></li>
   <li><a href="/manuals/accessibility.html">Building accessible services</a></li>
   <li><a href="/standards/pair-programming.html">Pair programming</a></li>
+  <li><a href="/standards/test-driven-development.html">Test-driven Development (TDD)</a></li>
   <li><a href="/standards/breaking-down-work.html">Breaking down work</a></li>
   <li><a href="/manuals/browser-support.html">Supporting different browsers</a></li>
   <li><a href="/standards/optimise-frontend-perf.html">How to optimise frontend performance</a></li>

source/partials/_svg-tdd-red-green-refactor.html.erb

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