exclude symlink directories from rage/doctor
exclude symlink directories from rage/doctor

Summary:
after adding the symlink to the last {command} log directory rage picks it as a normal
folder and lists the last command twice. From now on, ignore the symlinks and only
care about actual directories.

Test Plan:
- ci
- manual testing

Reviewed By: plamenko

fbshipit-source-id: 7e36e9d

k21/buck,clonetwin26/buck,shybovycha/buck,shs96c/buck,rmaz/buck,facebook/buck,k21/buck,k21/buck,marcinkwiatkowski/buck,shs96c/buck,romanoid/buck,rmaz/buck,dsyang/buck,shybovycha/buck,shybovycha/buck,JoelMarcey/buck,ilya-klyuchnikov/buck,clonetwin26/buck,rmaz/buck,dsyang/buck,facebook/buck,LegNeato/buck,robbertvanginkel/buck,zhan-xiong/buck,LegNeato/buck,Addepar/buck,JoelMarcey/buck,facebook/buck,shs96c/buck,zpao/buck,shybovycha/buck,robbertvanginkel/buck,ilya-klyuchnikov/buck,Addepar/buck,zhan-xiong/buck,k21/buck,clonetwin26/buck,rmaz/buck,ilya-klyuchnikov/buck,JoelMarcey/buck,k21/buck,kageiit/buck,romanoid/buck,JoelMarcey/buck,k21/buck,Addepar/buck,Addepar/buck,robbertvanginkel/buck,dsyang/buck,brettwooldridge/buck,kageiit/buck,robbertvanginkel/buck,k21/buck,brettwooldridge/buck,romanoid/buck,rmaz/buck,dsyang/buck,shs96c/buck,dsyang/buck,zhan-xiong/buck,Addepar/buck,SeleniumHQ/buck,clonetwin26/buck,clonetwin26/buck,LegNeato/buck,SeleniumHQ/buck,marcinkwiatkowski/buck,brettwooldridge/buck,zhan-xiong/buck,brettwooldridge/buck,ilya-klyuchnikov/buck,marcinkwiatkowski/buck,clonetwin26/buck,romanoid/buck,JoelMarcey/buck,shs96c/buck,marcinkwiatkowski/buck,zpao/buck,robbertvanginkel/buck,rmaz/buck,SeleniumHQ/buck,dsyang/buck,shybovycha/buck,SeleniumHQ/buck,LegNeato/buck,shs96c/buck,ilya-klyuchnikov/buck,SeleniumHQ/buck,rmaz/buck,LegNeato/buck,shybovycha/buck,brettwooldridge/buck,zhan-xiong/buck,romanoid/buck,robbertvanginkel/buck,zhan-xiong/buck,kageiit/buck,Addepar/buck,ilya-klyuchnikov/buck,SeleniumHQ/buck,Addepar/buck,shybovycha/buck,LegNeato/buck,zhan-xiong/buck,brettwooldridge/buck,robbertvanginkel/buck,shybovycha/buck,zpao/buck,LegNeato/buck,clonetwin26/buck,facebook/buck,LegNeato/buck,SeleniumHQ/buck,zpao/buck,clonetwin26/buck,clonetwin26/buck,Addepar/buck,Addepar/buck,facebook/buck,marcinkwiatkowski/buck,rmaz/buck,ilya-klyuchnikov/buck,romanoid/buck,dsyang/buck,zpao/buck,nguyentruongtho/buck,brettwooldridge/buck,romanoid/buck,rmaz/buck,robbertvanginkel/buck,ilya-klyuchnikov/buck,shs96c/buck,zhan-xiong/buck,brettwooldridge/buck,romanoid/buck,k21/buck,romanoid/buck,brettwooldridge/buck,zhan-xiong/buck,clonetwin26/buck,Addepar/buck,zpao/buck,brettwooldridge/buck,SeleniumHQ/buck,k21/buck,shs96c/buck,JoelMarcey/buck,SeleniumHQ/buck,SeleniumHQ/buck,LegNeato/buck,zpao/buck,marcinkwiatkowski/buck,zhan-xiong/buck,ilya-klyuchnikov/buck,robbertvanginkel/buck,kageiit/buck,rmaz/buck,marcinkwiatkowski/buck,shybovycha/buck,JoelMarcey/buck,dsyang/buck,k21/buck,kageiit/buck,dsyang/buck,marcinkwiatkowski/buck,k21/buck,dsyang/buck,nguyentruongtho/buck,k21/buck,shybovycha/buck,robbertvanginkel/buck,clonetwin26/buck,zhan-xiong/buck,shybovycha/buck,brettwooldridge/buck,kageiit/buck,ilya-klyuchnikov/buck,LegNeato/buck,JoelMarcey/buck,marcinkwiatkowski/buck,Addepar/buck,Addepar/buck,brettwooldridge/buck,clonetwin26/buck,romanoid/buck,marcinkwiatkowski/buck,zhan-xiong/buck,nguyentruongtho/buck,robbertvanginkel/buck,rmaz/buck,LegNeato/buck,marcinkwiatkowski/buck,dsyang/buck,robbertvanginkel/buck,dsyang/buck,zhan-xiong/buck,romanoid/buck,nguyentruongtho/buck,ilya-klyuchnikov/buck,facebook/buck,robbertvanginkel/buck,marcinkwiatkowski/buck,marcinkwiatkowski/buck,JoelMarcey/buck,JoelMarcey/buck,romanoid/buck,SeleniumHQ/buck,k21/buck,nguyentruongtho/buck,ilya-klyuchnikov/buck,SeleniumHQ/buck,rmaz/buck,LegNeato/buck,shybovycha/buck,shs96c/buck,ilya-klyuchnikov/buck,JoelMarcey/buck,JoelMarcey/buck,kageiit/buck,romanoid/buck,dsyang/buck,nguyentruongtho/buck,Addepar/buck,SeleniumHQ/buck,clonetwin26/buck,JoelMarcey/buck,brettwooldridge/buck,facebook/buck,shs96c/buck,nguyentruongtho/buck,shs96c/buck,rmaz/buck,shs96c/buck,LegNeato/buck,shybovycha/buck,shs96c/buck