added wallet files to .gitignore
added wallet files to .gitignore

pmconrad/graphene,bigoc/openchain,cryptonomex/graphene,bigoc/openchain,bitshares/bitshares-2,pmconrad/graphene,oxarbitrage/bitshares-core,peertracksinc/muse,bitshares/bitshares-2,bitsuperlab/cpp-play2,abitmore/bitshares-2,oxarbitrage/bitshares-core,pmconrad/graphene,cryptonomex/graphene,bigoc/openchain,peertracksinc/muse,bitshares/bitshares-2,bitshares/bitshares-2,peertracksinc/muse,oxarbitrage/bitshares-core,pmconrad/graphene,cryptonomex/graphene,bigoc/openchain,abitmore/bitshares-2,peertracksinc/muse,abitmore/bitshares-2,bitsuperlab/cpp-play2,bitsuperlab/cpp-play2,oxarbitrage/bitshares-core,abitmore/bitshares-2