travis: enable stream mounting and configure IPFS listeners

We need to enable the IPFS feature Experimental.Libp2pStreamMounting
in order to test the P2P APIs. To do so, we have to run `ipfs init`
manually so that the IPFS config file exists on disk. In addition, we
also have to configure Addresses.API and Addresses.Gateway, which were
previously set by the container at boot, because the container stops
setting those parameters if the IPFS configuration file already
exists.

.travis.yml

@@ -18,7 +18,11 @@ services:
 before_install:
 - docker pull ipfs/go-ipfs:master
 - mkdir /tmp/ipfs && chmod 0777 /tmp/ipfs
-- docker run -d -v /tmp/ipfs:/data/ipfs -p 8080:8080 -p 4001:4001 -p 5001:5001 ipfs/go-ipfs:master --enable-pubsub-experiment
+- docker run -v /tmp/ipfs:/data/ipfs --user ipfs --entrypoint "" ipfs/go-ipfs:master ipfs init
+- docker run -v /tmp/ipfs:/data/ipfs --user ipfs --entrypoint "" ipfs/go-ipfs:master ipfs config --json Experimental.Libp2pStreamMounting true
+- docker run -v /tmp/ipfs:/data/ipfs --user ipfs --entrypoint "" ipfs/go-ipfs:master ipfs config Addresses.API /ip4/0.0.0.0/tcp/5001
+- docker run -v /tmp/ipfs:/data/ipfs --user ipfs --entrypoint "" ipfs/go-ipfs:master ipfs config Addresses.Gateway /ip4/0.0.0.0/tcp/8080
+- docker run -d -v /tmp/ipfs:/data/ipfs -p 8080:8080 -p 4001:4001 -p 5001:5001 ipfs/go-ipfs:master daemon --enable-pubsub-experiment
 
 install:
   - go get -t -v ./...