Make scripts/diff_rulekeys.py handle UTF-8
Make scripts/diff_rulekeys.py handle UTF-8

Summary: This opens files as utf-8 by default.

Test Plan: CI

Reviewed By: nayrmi

fbshipit-source-id: a222e8e

darkforestzero/buck,daedric/buck,Addepar/buck,kageiit/buck,illicitonion/buck,kageiit/buck,zhan-xiong/buck,daedric/buck,robbertvanginkel/buck,rmaz/buck,raviagarwal7/buck,raviagarwal7/buck,marcinkwiatkowski/buck,illicitonion/buck,shybovycha/buck,nguyentruongtho/buck,zhan-xiong/buck,dsyang/buck,LegNeato/buck,daedric/buck,raviagarwal7/buck,brettwooldridge/buck,janicduplessis/buck,clonetwin26/buck,Addepar/buck,darkforestzero/buck,daedric/buck,sdwilsh/buck,sdwilsh/buck,nguyentruongtho/buck,grumpyjames/buck,marcinkwiatkowski/buck,SeleniumHQ/buck,SeleniumHQ/buck,brettwooldridge/buck,ilya-klyuchnikov/buck,janicduplessis/buck,illicitonion/buck,facebook/buck,rmaz/buck,raviagarwal7/buck,justinmuller/buck,JoelMarcey/buck,LegNeato/buck,nguyentruongtho/buck,marcinkwiatkowski/buck,darkforestzero/buck,dsyang/buck,shs96c/buck,shs96c/buck,justinmuller/buck,sdwilsh/buck,shybovycha/buck,rmaz/buck,davido/buck,k21/buck,justinmuller/buck,raviagarwal7/buck,ilya-klyuchnikov/buck,marcinkwiatkowski/buck,clonetwin26/buck,grumpyjames/buck,grumpyjames/buck,zhan-xiong/buck,sdwilsh/buck,shs96c/buck,brettwooldridge/buck,grumpyjames/buck,darkforestzero/buck,dsyang/buck,vschs007/buck,zpao/buck,facebook/buck,kageiit/buck,brettwooldridge/buck,ilya-klyuchnikov/buck,shs96c/buck,shs96c/buck,robbertvanginkel/buck,brettwooldridge/buck,grumpyjames/buck,vschs007/buck,clonetwin26/buck,clonetwin26/buck,justinmuller/buck,rmaz/buck,justinmuller/buck,JoelMarcey/buck,davido/buck,dsyang/buck,k21/buck,shybovycha/buck,SeleniumHQ/buck,clonetwin26/buck,daedric/buck,davido/buck,davido/buck,marcinkwiatkowski/buck,darkforestzero/buck,robbertvanginkel/buck,daedric/buck,Addepar/buck,romanoid/buck,vschs007/buck,k21/buck,vschs007/buck,dsyang/buck,illicitonion/buck,robbertvanginkel/buck,OkBuilds/buck,JoelMarcey/buck,dsyang/buck,romanoid/buck,brettwooldridge/buck,shs96c/buck,zpao/buck,zhan-xiong/buck,facebook/buck,OkBuilds/buck,daedric/buck,LegNeato/buck,shybovycha/buck,grumpyjames/buck,grumpyjames/buck,janicduplessis/buck,robbertvanginkel/buck,sdwilsh/buck,Addepar/buck,vschs007/buck,brettwooldridge/buck,LegNeato/buck,shybovycha/buck,vschs007/buck,raviagarwal7/buck,kageiit/buck,clonetwin26/buck,sdwilsh/buck,SeleniumHQ/buck,clonetwin26/buck,shybovycha/buck,dsyang/buck,LegNeato/buck,daedric/buck,dsyang/buck,LegNeato/buck,shs96c/buck,LegNeato/buck,nguyentruongtho/buck,justinmuller/buck,nguyentruongtho/buck,robbertvanginkel/buck,davido/buck,zhan-xiong/buck,davido/buck,rmaz/buck,raviagarwal7/buck,LegNeato/buck,sdwilsh/buck,daedric/buck,brettwooldridge/buck,marcinkwiatkowski/buck,vschs007/buck,davido/buck,SeleniumHQ/buck,nguyentruongtho/buck,janicduplessis/buck,raviagarwal7/buck,zhan-xiong/buck,vschs007/buck,zpao/buck,shybovycha/buck,zpao/buck,LegNeato/buck,romanoid/buck,vschs007/buck,shs96c/buck,zpao/buck,LegNeato/buck,Addepar/buck,SeleniumHQ/buck,davido/buck,zhan-xiong/buck,zhan-xiong/buck,SeleniumHQ/buck,zhan-xiong/buck,marcinkwiatkowski/buck,JoelMarcey/buck,zhan-xiong/buck,JoelMarcey/buck,davido/buck,ilya-klyuchnikov/buck,romanoid/buck,k21/buck,ilya-klyuchnikov/buck,JoelMarcey/buck,facebook/buck,romanoid/buck,shs96c/buck,justinmuller/buck,facebook/buck,justinmuller/buck,davido/buck,rmaz/buck,illicitonion/buck,clonetwin26/buck,zpao/buck,rmaz/buck,robbertvanginkel/buck,raviagarwal7/buck,SeleniumHQ/buck,marcinkwiatkowski/buck,janicduplessis/buck,OkBuilds/buck,ilya-klyuchnikov/buck,vschs007/buck,janicduplessis/buck,illicitonion/buck,JoelMarcey/buck,OkBuilds/buck,romanoid/buck,darkforestzero/buck,Addepar/buck,robbertvanginkel/buck,SeleniumHQ/buck,k21/buck,justinmuller/buck,Addepar/buck,sdwilsh/buck,raviagarwal7/buck,Addepar/buck,dsyang/buck,janicduplessis/buck,grumpyjames/buck,ilya-klyuchnikov/buck,rmaz/buck,shybovycha/buck,zpao/buck,clonetwin26/buck,janicduplessis/buck,darkforestzero/buck,daedric/buck,romanoid/buck,daedric/buck,shybovycha/buck,clonetwin26/buck,rmaz/buck,sdwilsh/buck,k21/buck,zhan-xiong/buck,LegNeato/buck,sdwilsh/buck,OkBuilds/buck,clonetwin26/buck,kageiit/buck,OkBuilds/buck,illicitonion/buck,robbertvanginkel/buck,sdwilsh/buck,OkBuilds/buck,justinmuller/buck,shybovycha/buck,JoelMarcey/buck,JoelMarcey/buck,justinmuller/buck,rmaz/buck,OkBuilds/buck,justinmuller/buck,brettwooldridge/buck,OkBuilds/buck,SeleniumHQ/buck,k21/buck,ilya-klyuchnikov/buck,rmaz/buck,OkBuilds/buck,darkforestzero/buck,romanoid/buck,marcinkwiatkowski/buck,JoelMarcey/buck,raviagarwal7/buck,daedric/buck,OkBuilds/buck,romanoid/buck,k21/buck,JoelMarcey/buck,darkforestzero/buck,dsyang/buck,shs96c/buck,raviagarwal7/buck,illicitonion/buck,Addepar/buck,shybovycha/buck,janicduplessis/buck,shs96c/buck,romanoid/buck,SeleniumHQ/buck,ilya-klyuchnikov/buck,Addepar/buck,rmaz/buck,k21/buck,illicitonion/buck,LegNeato/buck,ilya-klyuchnikov/buck,sdwilsh/buck,illicitonion/buck,k21/buck,marcinkwiatkowski/buck,daedric/buck,rmaz/buck,davido/buck,davido/buck,brettwooldridge/buck,grumpyjames/buck,robbertvanginkel/buck,marcinkwiatkowski/buck,darkforestzero/buck,illicitonion/buck,shybovycha/buck,vschs007/buck,nguyentruongtho/buck,janicduplessis/buck,clonetwin26/buck,grumpyjames/buck,brettwooldridge/buck,raviagarwal7/buck,shybovycha/buck,zhan-xiong/buck,dsyang/buck,k21/buck,OkBuilds/buck,brettwooldridge/buck,marcinkwiatkowski/buck,vschs007/buck,Addepar/buck,robbertvanginkel/buck,robbertvanginkel/buck,brettwooldridge/buck,Addepar/buck,darkforestzero/buck,grumpyjames/buck,kageiit/buck,romanoid/buck,robbertvanginkel/buck,SeleniumHQ/buck,janicduplessis/buck,romanoid/buck,shs96c/buck,illicitonion/buck,clonetwin26/buck,ilya-klyuchnikov/buck,davido/buck,OkBuilds/buck,justinmuller/buck,shs96c/buck,ilya-klyuchnikov/buck,dsyang/buck,darkforestzero/buck,illicitonion/buck,darkforestzero/buck,k21/buck,facebook/buck,k21/buck,zhan-xiong/buck,sdwilsh/buck,marcinkwiatkowski/buck,LegNeato/buck,JoelMarcey/buck,romanoid/buck,kageiit/buck,Addepar/buck,janicduplessis/buck,SeleniumHQ/buck,facebook/buck,grumpyjames/buck,JoelMarcey/buck,dsyang/buck,ilya-klyuchnikov/buck,vschs007/buck