Fix link to wrong version of Jasmine

Applies to #5354

docs/writing-specs.md

@@ -1,6 +1,6 @@
 # Writing specs
 
-Atom uses [Jasmine](http://jasmine.github.io/2.0/introduction.html) as its spec framework. Any new functionality should have specs to guard against regressions.
+Atom uses [Jasmine](http://jasmine.github.io/1.3/introduction.html) as its spec framework. Any new functionality should have specs to guard against regressions.
 
 ## Create a new spec