Upgrade go.mod yamux to 1.1.5 (#257)

Fixes race conditions in the tests when using go modules.

go.mod

@@ -70,6 +70,6 @@ require (
 	github.com/whyrusleeping/go-smux-yamux v2.0.8+incompatible // indirect
 	github.com/whyrusleeping/mafmt v1.2.8 // indirect
 	github.com/whyrusleeping/multiaddr-filter v0.0.0-20160516205228-e903e4adabd7 // indirect
-	github.com/whyrusleeping/yamux v1.1.2 // indirect
+	github.com/whyrusleeping/yamux v1.1.5 // indirect
 	golang.org/x/net v0.0.0-20190119204137-ed066c81e75e // indirect
 )

go.sum

@@ -195,9 +195,9 @@ github.com/whyrusleeping/mafmt v1.2.8 h1:TCghSl5kkwEE0j+sU/gudyhVMRlpBin8fMBBHg5
 github.com/whyrusleeping/mafmt v1.2.8/go.mod h1:faQJFPbLSxzD9xpA02ttW/tS9vZykNvXwGvqIpk20FA=
 github.com/whyrusleeping/multiaddr-filter v0.0.0-20160516205228-e903e4adabd7 h1:E9S12nwJwEOXe2d6gT6qxdvqMnNq+VnSsKPgm2ZZNds=
 github.com/whyrusleeping/multiaddr-filter v0.0.0-20160516205228-e903e4adabd7/go.mod h1:X2c0RVCI1eSUFI8eLcY3c0423ykwiUdxLJtkDvruhjI=
-github.com/whyrusleeping/yamux v1.1.2 h1:oGpjhLpa0mZnRMbthCkEe+61VvkQGFSkQgm9WvaHgRU=
-github.com/whyrusleeping/yamux v1.1.2/go.mod h1:E8LnQQ8HKx5KD29HZFUwM1PxCOdPRzGwur1mcYhXcD8=
-golang.org/x/crypto v0.0.0-20170930174604-9419663f5a44/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
+github.com/whyrusleeping/yamux v1.1.5 h1:4CK3aUUJQu0qpKZv5gEWJjNOQtdbdDhVVS6PJ+HimdE=
+github.com/whyrusleeping/yamux v1.1.5/go.mod h1:E8LnQQ8HKx5KD29HZFUwM1PxCOdPRzGwur1mcYhXcD8=
+golang.org/x/crypto v0.0.0-20170930174604-9419663f5a44 h1:9lP3x0pW80sDI6t1UMSLA4to18W7R7imwAI/sWS9S8Q=
 golang.org/x/crypto v0.0.0-20181203042331-505ab145d0a9 h1:mKdxBk7AujPs8kU4m80U72y/zjbZ3UcXC7dClwKbUI0=
 golang.org/x/crypto v0.0.0-20181203042331-505ab145d0a9/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/net v0.0.0-20180524181706-dfa909b99c79/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=