Run 'ant clean' in perftest.
Run 'ant clean' in perftest.

Summary:
I noticed the failing runs would not print 'Building buck...', meaning
the buck repo might not be in a clean state. This should make sure
we're not reusing a stale binary in the perf test.

Test Plan: CI

Reviewed By: Coneko

fbshipit-source-id: 7546312

illicitonion/buck,marcinkwiatkowski/buck,rmaz/buck,brettwooldridge/buck,illicitonion/buck,grumpyjames/buck,shs96c/buck,illicitonion/buck,sdwilsh/buck,LegNeato/buck,sdwilsh/buck,LegNeato/buck,vschs007/buck,clonetwin26/buck,zhan-xiong/buck,rmaz/buck,Addepar/buck,JoelMarcey/buck,robbertvanginkel/buck,brettwooldridge/buck,rmaz/buck,clonetwin26/buck,vschs007/buck,brettwooldridge/buck,shybovycha/buck,marcinkwiatkowski/buck,romanoid/buck,romanoid/buck,Addepar/buck,LegNeato/buck,k21/buck,vschs007/buck,shs96c/buck,brettwooldridge/buck,rmaz/buck,davido/buck,zhan-xiong/buck,zpao/buck,grumpyjames/buck,k21/buck,romanoid/buck,justinmuller/buck,rmaz/buck,darkforestzero/buck,romanoid/buck,LegNeato/buck,vschs007/buck,vschs007/buck,k21/buck,clonetwin26/buck,ilya-klyuchnikov/buck,zpao/buck,vschs007/buck,nguyentruongtho/buck,dsyang/buck,brettwooldridge/buck,illicitonion/buck,sdwilsh/buck,robbertvanginkel/buck,Addepar/buck,rmaz/buck,SeleniumHQ/buck,shybovycha/buck,nguyentruongtho/buck,zhan-xiong/buck,davido/buck,dsyang/buck,illicitonion/buck,k21/buck,robbertvanginkel/buck,clonetwin26/buck,marcinkwiatkowski/buck,robbertvanginkel/buck,clonetwin26/buck,rmaz/buck,SeleniumHQ/buck,clonetwin26/buck,facebook/buck,dsyang/buck,vschs007/buck,darkforestzero/buck,zhan-xiong/buck,SeleniumHQ/buck,grumpyjames/buck,k21/buck,darkforestzero/buck,romanoid/buck,brettwooldridge/buck,Addepar/buck,clonetwin26/buck,davido/buck,grumpyjames/buck,SeleniumHQ/buck,darkforestzero/buck,sdwilsh/buck,JoelMarcey/buck,shybovycha/buck,SeleniumHQ/buck,zhan-xiong/buck,robbertvanginkel/buck,darkforestzero/buck,zpao/buck,robbertvanginkel/buck,sdwilsh/buck,JoelMarcey/buck,robbertvanginkel/buck,shybovycha/buck,SeleniumHQ/buck,justinmuller/buck,justinmuller/buck,shs96c/buck,SeleniumHQ/buck,shybovycha/buck,illicitonion/buck,zpao/buck,SeleniumHQ/buck,rmaz/buck,kageiit/buck,k21/buck,ilya-klyuchnikov/buck,daedric/buck,daedric/buck,shs96c/buck,nguyentruongtho/buck,LegNeato/buck,brettwooldridge/buck,Addepar/buck,justinmuller/buck,marcinkwiatkowski/buck,JoelMarcey/buck,grumpyjames/buck,nguyentruongtho/buck,clonetwin26/buck,Addepar/buck,romanoid/buck,shybovycha/buck,k21/buck,shybovycha/buck,LegNeato/buck,justinmuller/buck,Addepar/buck,daedric/buck,illicitonion/buck,darkforestzero/buck,robbertvanginkel/buck,rmaz/buck,justinmuller/buck,daedric/buck,illicitonion/buck,k21/buck,sdwilsh/buck,SeleniumHQ/buck,justinmuller/buck,clonetwin26/buck,LegNeato/buck,shybovycha/buck,SeleniumHQ/buck,zhan-xiong/buck,LegNeato/buck,romanoid/buck,dsyang/buck,brettwooldridge/buck,romanoid/buck,zhan-xiong/buck,romanoid/buck,davido/buck,marcinkwiatkowski/buck,dsyang/buck,robbertvanginkel/buck,Addepar/buck,illicitonion/buck,davido/buck,rmaz/buck,romanoid/buck,vschs007/buck,sdwilsh/buck,marcinkwiatkowski/buck,justinmuller/buck,dsyang/buck,dsyang/buck,shs96c/buck,justinmuller/buck,shs96c/buck,illicitonion/buck,darkforestzero/buck,kageiit/buck,grumpyjames/buck,k21/buck,grumpyjames/buck,clonetwin26/buck,JoelMarcey/buck,shs96c/buck,facebook/buck,shybovycha/buck,darkforestzero/buck,daedric/buck,marcinkwiatkowski/buck,vschs007/buck,justinmuller/buck,grumpyjames/buck,dsyang/buck,kageiit/buck,shybovycha/buck,marcinkwiatkowski/buck,zhan-xiong/buck,zpao/buck,marcinkwiatkowski/buck,nguyentruongtho/buck,daedric/buck,LegNeato/buck,ilya-klyuchnikov/buck,JoelMarcey/buck,davido/buck,robbertvanginkel/buck,nguyentruongtho/buck,justinmuller/buck,daedric/buck,daedric/buck,facebook/buck,ilya-klyuchnikov/buck,LegNeato/buck,SeleniumHQ/buck,shybovycha/buck,sdwilsh/buck,zpao/buck,daedric/buck,shs96c/buck,SeleniumHQ/buck,ilya-klyuchnikov/buck,JoelMarcey/buck,illicitonion/buck,sdwilsh/buck,clonetwin26/buck,vschs007/buck,shs96c/buck,robbertvanginkel/buck,vschs007/buck,dsyang/buck,nguyentruongtho/buck,daedric/buck,justinmuller/buck,davido/buck,daedric/buck,grumpyjames/buck,Addepar/buck,kageiit/buck,JoelMarcey/buck,marcinkwiatkowski/buck,rmaz/buck,zhan-xiong/buck,k21/buck,zpao/buck,zhan-xiong/buck,marcinkwiatkowski/buck,shybovycha/buck,k21/buck,clonetwin26/buck,ilya-klyuchnikov/buck,robbertvanginkel/buck,kageiit/buck,dsyang/buck,davido/buck,ilya-klyuchnikov/buck,ilya-klyuchnikov/buck,ilya-klyuchnikov/buck,sdwilsh/buck,marcinkwiatkowski/buck,shybovycha/buck,darkforestzero/buck,k21/buck,dsyang/buck,shs96c/buck,JoelMarcey/buck,justinmuller/buck,vschs007/buck,romanoid/buck,shs96c/buck,vschs007/buck,JoelMarcey/buck,Addepar/buck,sdwilsh/buck,LegNeato/buck,Addepar/buck,facebook/buck,grumpyjames/buck,brettwooldridge/buck,shs96c/buck,darkforestzero/buck,davido/buck,JoelMarcey/buck,JoelMarcey/buck,LegNeato/buck,romanoid/buck,darkforestzero/buck,sdwilsh/buck,ilya-klyuchnikov/buck,Addepar/buck,davido/buck,ilya-klyuchnikov/buck,SeleniumHQ/buck,sdwilsh/buck,zhan-xiong/buck,davido/buck,darkforestzero/buck,darkforestzero/buck,rmaz/buck,dsyang/buck,JoelMarcey/buck,rmaz/buck,facebook/buck,shs96c/buck,grumpyjames/buck,brettwooldridge/buck,zhan-xiong/buck,facebook/buck,daedric/buck,ilya-klyuchnikov/buck,davido/buck,kageiit/buck,robbertvanginkel/buck,brettwooldridge/buck,illicitonion/buck,LegNeato/buck,dsyang/buck,illicitonion/buck,marcinkwiatkowski/buck,grumpyjames/buck,facebook/buck,ilya-klyuchnikov/buck,Addepar/buck,davido/buck,k21/buck,daedric/buck,zhan-xiong/buck,brettwooldridge/buck,brettwooldridge/buck,kageiit/buck,clonetwin26/buck,romanoid/buck