Add missing PyPy SPLIT=4/4 build to Travis
Add missing PyPy SPLIT=4/4 build to Travis

rahuldan/sympy,kaichogami/sympy,souravsingh/sympy,lindsayad/sympy,kaichogami/sympy,hargup/sympy,jerli/sympy,skidzo/sympy,rahuldan/sympy,kaushik94/sympy,chaffra/sympy,Titan-C/sympy,jaimahajan1997/sympy,madan96/sympy,souravsingh/sympy,jerli/sympy,souravsingh/sympy,aktech/sympy,hargup/sympy,Titan-C/sympy,Curious72/sympy,sampadsaha5/sympy,postvakje/sympy,kaichogami/sympy,ChristinaZografou/sympy,postvakje/sympy,skidzo/sympy,jaimahajan1997/sympy,chaffra/sympy,Curious72/sympy,chaffra/sympy,yashsharan/sympy,mafiya69/sympy,mafiya69/sympy,madan96/sympy,kaushik94/sympy,lindsayad/sympy,kaushik94/sympy,yashsharan/sympy,drufat/sympy,drufat/sympy,rahuldan/sympy,yashsharan/sympy,skidzo/sympy,ChristinaZografou/sympy,drufat/sympy,sampadsaha5/sympy,postvakje/sympy,aktech/sympy,jaimahajan1997/sympy,mafiya69/sympy,lindsayad/sympy,Titan-C/sympy,jerli/sympy,hargup/sympy,madan96/sympy,Curious72/sympy,sampadsaha5/sympy,ChristinaZografou/sympy,aktech/sympy