Fixed an incorrect instruction in getting-started webpage.
Fixed an incorrect instruction in getting-started webpage.

In the Running Unit Tests section of www.reviewboard.org/docs/codebase/dev/
getting-started/ page, changed from "./manage.py test" to "./reviewboard/ma
nage.py test". This fix will make sure users will run the script in the cor
rect directory.

chazy/reviewboard,1tush/reviewboard,KnowNo/reviewboard,davidt/reviewboard,reviewboard/reviewboard,chazy/reviewboard,beol/reviewboard,bkochendorfer/reviewboard,chazy/reviewboard,atagar/ReviewBoard,custode/reviewboard,Khan/reviewboard,Khan/reviewboard,bkochendorfer/reviewboard,Khan/reviewboard,KnowNo/reviewboard,atagar/ReviewBoard,1tush/reviewboard,atagar/ReviewBoard,chazy/reviewboard,Khan/reviewboard,chipx86/reviewboard,custode/reviewboard,atagar/ReviewBoard,sgallagher/reviewboard,1tush/reviewboard,brennie/reviewboard,Khan/reviewboard,Khan/reviewboard,KnowNo/reviewboard,custode/reviewboard,chazy/reviewboard,reviewboard/reviewboard,davidt/reviewboard,1tush/reviewboard,custode/reviewboard,chazy/reviewboard,chipx86/reviewboard,chazy/reviewboard,sgallagher/reviewboard,reviewboard/reviewboard,1tush/reviewboard,chazy/reviewboard,KnowNo/reviewboard,brennie/reviewboard,atagar/ReviewBoard,chipx86/reviewboard,reviewboard/reviewboard,atagar/ReviewBoard,Khan/reviewboard,sgallagher/reviewboard,sgallagher/reviewboard,1tush/reviewboard,davidt/reviewboard,1tush/reviewboard,chazy/reviewboard,1tush/reviewboard,atagar/ReviewBoard,bkochendorfer/reviewboard,chipx86/reviewboard,beol/reviewboard,Khan/reviewboard,davidt/reviewboard,atagar/ReviewBoard,atagar/ReviewBoard,1tush/reviewboard,Khan/reviewboard,beol/reviewboard,beol/reviewboard,brennie/reviewboard,bkochendorfer/reviewboard,brennie/reviewboard