Add info about GSoC 2015, 2016
Add info about GSoC 2015, 2016

skidzo/sympy,madan96/sympy,madan96/sympy,madan96/sympy,chaffra/sympy,kaushik94/sympy,yashsharan/sympy,kaushik94/sympy,yashsharan/sympy,yashsharan/sympy,kaushik94/sympy,chaffra/sympy,skidzo/sympy,jaimahajan1997/sympy,jaimahajan1997/sympy,jaimahajan1997/sympy,chaffra/sympy,skidzo/sympy