simplify/hyperexpand: Add __hash__ to Mod1
simplify/hyperexpand: Add __hash__ to Mod1

Add a __hash__ method to Mod1. We need one to allow adding Mod1 objects
to dicts in Python 3. The hash is simple as it's not supposed to be used
for anything (per the class doc).

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