Upgrade to python-coveralls 2.4.3.
Upgrade to python-coveralls 2.4.3.

* Fix import error in some CI environments.

bglassy/OpenBazaar,saltduck/OpenBazaar,atsuyim/OpenBazaar,tortxof/OpenBazaar,habibmasuro/OpenBazaar,Renelvon/OpenBazaar,rllola/OpenBazaar,atsuyim/OpenBazaar,Renelvon/OpenBazaar,habibmasuro/OpenBazaar,im0rtel/OpenBazaar,matiasbastos/OpenBazaar,freebazaar/FreeBazaar,bglassy/OpenBazaar,dionyziz/OpenBazaar,akhavr/OpenBazaar,atsuyim/OpenBazaar,mirrax/OpenBazaar,bankonme/OpenBazaar,freebazaar/FreeBazaar,saltduck/OpenBazaar,NolanZhao/OpenBazaar,im0rtel/OpenBazaar,blakejakopovic/OpenBazaar,matiasbastos/OpenBazaar,im0rtel/OpenBazaar,must-/OpenBazaar,NolanZhao/OpenBazaar,im0rtel/OpenBazaar,freebazaar/FreeBazaar,akhavr/OpenBazaar,dionyziz/OpenBazaar,mirrax/OpenBazaar,freebazaar/FreeBazaar,dionyziz/OpenBazaar,dionyziz/OpenBazaar,matiasbastos/OpenBazaar,rllola/OpenBazaar,bankonme/OpenBazaar,dionyziz/OpenBazaar,Renelvon/OpenBazaar,atsuyim/OpenBazaar,tortxof/OpenBazaar,must-/OpenBazaar,matiasbastos/OpenBazaar,mirrax/OpenBazaar,bglassy/OpenBazaar,saltduck/OpenBazaar,akhavr/OpenBazaar,bankonme/OpenBazaar,NolanZhao/OpenBazaar,tortxof/OpenBazaar,rllola/OpenBazaar,Renelvon/OpenBazaar,mirrax/OpenBazaar,bankonme/OpenBazaar,must-/OpenBazaar,tortxof/OpenBazaar,akhavr/OpenBazaar,blakejakopovic/OpenBazaar,must-/OpenBazaar,bglassy/OpenBazaar,freebazaar/FreeBazaar,rllola/OpenBazaar,habibmasuro/OpenBazaar,blakejakopovic/OpenBazaar,blakejakopovic/OpenBazaar,akhavr/OpenBazaar,habibmasuro/OpenBazaar,saltduck/OpenBazaar,NolanZhao/OpenBazaar