preview: docstring update, use os.system instead of pexpect
preview: docstring update, use os.system instead of pexpect

Signed-off-by: Vinzent Steinberg <72fdda149f36f4b33dc36ed5d23df8c1c631dae1@gmail.com>
Signed-off-by: Ondrej Certik <b816faa87b7d35274d2e545c5be11ed4376f3ccf@certik.cz>

Shaswat27/sympy,hrashk/sympy,sampadsaha5/sympy,yashsharan/sympy,lidavidm/sympy,toolforger/sympy,yukoba/sympy,toolforger/sympy,kaushik94/sympy,kumarkrishna/sympy,mafiya69/sympy,aktech/sympy,MridulS/sympy,pandeyadarsh/sympy,cccfran/sympy,kaichogami/sympy,liangjiaxing/sympy,sunny94/temp,MechCoder/sympy,toolforger/sympy,sahmed95/sympy,souravsingh/sympy,sahmed95/sympy,ChristinaZografou/sympy,emon10005/sympy,asm666/sympy,bukzor/sympy,moble/sympy,Vishluck/sympy,chaffra/sympy,wanglongqi/sympy,moble/sympy,Designist/sympy,shikil/sympy,chaffra/sympy,wanglongqi/sympy,oliverlee/sympy,Curious72/sympy,mcdaniel67/sympy,Sumith1896/sympy,hrashk/sympy,asm666/sympy,kevalds51/sympy,AkademieOlympia/sympy,kumarkrishna/sympy,vipulroxx/sympy,beni55/sympy,mafiya69/sympy,oliverlee/sympy,wyom/sympy,Davidjohnwilson/sympy,ahhda/sympy,MridulS/sympy,wyom/sympy,ChristinaZografou/sympy,emon10005/sympy,yashsharan/sympy,cswiercz/sympy,maniteja123/sympy,saurabhjn76/sympy,jamesblunt/sympy,rahuldan/sympy,hargup/sympy,cswiercz/sympy,minrk/sympy,lidavidm/sympy,madan96/sympy,garvitr/sympy,abloomston/sympy,hargup/sympy,yukoba/sympy,skidzo/sympy,sampadsaha5/sympy,Mitchkoens/sympy,wyom/sympy,kevalds51/sympy,yukoba/sympy,atsao72/sympy,lidavidm/sympy,maniteja123/sympy,amitjamadagni/sympy,abloomston/sympy,AkademieOlympia/sympy,madan96/sympy,kmacinnis/sympy,cccfran/sympy,pbrady/sympy,Sumith1896/sympy,Sumith1896/sympy,shikil/sympy,jbbskinny/sympy,Mitchkoens/sympy,VaibhavAgarwalVA/sympy,MechCoder/sympy,sahilshekhawat/sympy,Gadal/sympy,MechCoder/sympy,ga7g08/sympy,lindsayad/sympy,kumarkrishna/sympy,skidzo/sympy,Titan-C/sympy,wanglongqi/sympy,iamutkarshtiwari/sympy,vipulroxx/sympy,Vishluck/sympy,fperez/sympy,srjoglekar246/sympy,maniteja123/sympy,abhiii5459/sympy,jerli/sympy,kmacinnis/sympy,souravsingh/sympy,Designist/sympy,Davidjohnwilson/sympy,postvakje/sympy,cccfran/sympy,drufat/sympy,grevutiu-gabriel/sympy,drufat/sympy,grevutiu-gabriel/sympy,Shaswat27/sympy,saurabhjn76/sympy,abhiii5459/sympy,iamutkarshtiwari/sympy,abhiii5459/sympy,bukzor/sympy,dqnykamp/sympy,saurabhjn76/sympy,ChristinaZografou/sympy,garvitr/sympy,AunShiLord/sympy,sunny94/temp,postvakje/sympy,debugger22/sympy,atsao72/sympy,dqnykamp/sympy,madan96/sympy,jamesblunt/sympy,pandeyadarsh/sympy,dqnykamp/sympy,VaibhavAgarwalVA/sympy,kmacinnis/sympy,jaimahajan1997/sympy,jamesblunt/sympy,sahmed95/sympy,shipci/sympy,liangjiaxing/sympy,sampadsaha5/sympy,Curious72/sympy,atreyv/sympy,mattpap/sympy-polys,kevalds51/sympy,farhaanbukhsh/sympy,amitjamadagni/sympy,emon10005/sympy,pernici/sympy,asm666/sympy,mcdaniel67/sympy,atsao72/sympy,Mitchkoens/sympy,meghana1995/sympy,farhaanbukhsh/sympy,jerli/sympy,vipulroxx/sympy,iamutkarshtiwari/sympy,kaushik94/sympy,mcdaniel67/sympy,minrk/sympy,souravsingh/sympy,yashsharan/sympy,kaushik94/sympy,moble/sympy,VaibhavAgarwalVA/sympy,chaffra/sympy,Curious72/sympy,Vishluck/sympy,Shaswat27/sympy,ga7g08/sympy,hargup/sympy,rahuldan/sympy,bukzor/sympy,lindsayad/sympy,Arafatk/sympy,jaimahajan1997/sympy,meghana1995/sympy,pandeyadarsh/sympy,liangjiaxing/sympy,kaichogami/sympy,shipci/sympy,kaichogami/sympy,ahhda/sympy,sahilshekhawat/sympy,Gadal/sympy,garvitr/sympy,drufat/sympy,Designist/sympy,MridulS/sympy,Titan-C/sympy,pbrady/sympy,postvakje/sympy,beni55/sympy,grevutiu-gabriel/sympy,diofant/diofant,AunShiLord/sympy,oliverlee/sympy,skidzo/sympy,cswiercz/sympy,AunShiLord/sympy,ga7g08/sympy,shipci/sympy,jbbskinny/sympy,pbrady/sympy,skirpichev/omg,atreyv/sympy,aktech/sympy,tovrstra/sympy,Davidjohnwilson/sympy,jerli/sympy,abloomston/sympy,debugger22/sympy,Gadal/sympy,ahhda/sympy,jaimahajan1997/sympy,debugger22/sympy,aktech/sympy,farhaanbukhsh/sympy,sahilshekhawat/sympy,AkademieOlympia/sympy,hrashk/sympy,shikil/sympy,rahuldan/sympy,meghana1995/sympy,jbbskinny/sympy,lindsayad/sympy,sunny94/temp,Titan-C/sympy,Arafatk/sympy,mafiya69/sympy,Arafatk/sympy,flacjacket/sympy,atreyv/sympy,beni55/sympy