Add test for pi_eq_proofs.
Add test for pi_eq_proofs.

letouzey/coq-wip,Matafou/coq,ejgallego/coq,letouzey/coq-wip,Lionel-Rieg/coq,SkySkimmer/coq,gares/coq,ppedrot/coq,silene/coq,JasonGross/coq,letouzey/coq-wip,ejgallego/coq,Matafou/coq,SkySkimmer/coq,amintimany/coq,Zimmi48/coq,william-lawvere/coq,maximedenes/coq,maximedenes/coq,ejgallego/coq,coq/coq,Ptival/coq,JasonGross/coq,Ptival/coq,maximedenes/coq,gares/coq,letouzey/coq-wip,maximedenes/coq,coq/coq,Ptival/coq,amintimany/coq,coq/coq,coq/coq,Zimmi48/coq,JasonGross/coq,Zimmi48/coq,william-lawvere/coq,ppedrot/coq,ppedrot/coq,JasonGross/coq,amintimany/coq,Lionel-Rieg/coq,maximedenes/coq,ppedrot/coq,SkySkimmer/coq,silene/coq,silene/coq,Lionel-Rieg/coq,Zimmi48/coq,letouzey/coq-wip,gares/coq,ejgallego/coq,gares/coq,SkySkimmer/coq,william-lawvere/coq,ppedrot/coq,Matafou/coq,gares/coq