Add go mod

.travis.yml

 os:
   - linux
 
-sudo: true
-
 language: go
 
 go:
-    - 1.11
+  - 1.11.x
+
+env:
+  global:
+    - GOTFLAGS="-race"
+  matrix:
+    - BUILD_DEPTYPE=gx
+    - BUILD_DEPTYPE=gomod
+
 
+# disable travis install
 install:
-  - make deps
+  - true
 
 script:
   - bash <(curl -s https://raw.githubusercontent.com/ipfs/ci-helpers/master/travis-ci/run-standard-tests.sh)
 
+
 cache:
-    directories:
-        - $GOPATH/src/gx
+  directories:
+    - $GOPATH/src/gx
+    - $GOPATH/pkg/mod
+    - /home/travis/.cache/go-build
 
 notifications:
   email: false
-
-env: GOTFLAGS="-race"

go.mod

+module github.com/multiformats/go-multiaddr-net
+
+require (
+	github.com/multiformats/go-multiaddr v0.0.1
+	github.com/multiformats/go-multiaddr-dns v0.0.1
+)

go.sum

+github.com/gxed/hashland/keccakpg v0.0.1 h1:wrk3uMNaMxbXiHibbPO4S0ymqJMm41WiudyFSs7UnsU=
+github.com/gxed/hashland/keccakpg v0.0.1/go.mod h1:kRzw3HkwxFU1mpmPP8v1WyQzwdGfmKFJ6tItnhQ67kU=
+github.com/gxed/hashland/murmur3 v0.0.1 h1:SheiaIt0sda5K+8FLz952/1iWS9zrnKsEJaOJu4ZbSc=
+github.com/gxed/hashland/murmur3 v0.0.1/go.mod h1:KjXop02n4/ckmZSnY2+HKcLud/tcmvhST0bie/0lS48=
+github.com/minio/blake2b-simd v0.0.0-20160723061019-3f5f724cb5b1 h1:lYpkrQH5ajf0OXOcUbGjvZxxijuBwbbmlSxLiuofa+g=
+github.com/minio/blake2b-simd v0.0.0-20160723061019-3f5f724cb5b1/go.mod h1:pD8RvIylQ358TN4wwqatJ8rNavkEINozVn9DtGI3dfQ=
+github.com/minio/sha256-simd v0.0.0-20190131020904-2d45a736cd16 h1:5W7KhL8HVF3XCFOweFD3BNESdnO8ewyYTFT2R+/b8FQ=
+github.com/minio/sha256-simd v0.0.0-20190131020904-2d45a736cd16/go.mod h1:2FMWW+8GMoPweT6+pI63m9YE3Lmw4J71hV56Chs1E/U=
+github.com/mr-tron/base58 v1.1.0 h1:Y51FGVJ91WBqCEabAi5OPUz38eAx8DakuAm5svLcsfQ=
+github.com/mr-tron/base58 v1.1.0/go.mod h1:xcD2VGqlgYjBdcBLw+TuYLr8afG+Hj8g2eTVqeSzSU8=
+github.com/multiformats/go-multiaddr v0.0.1 h1:/QUV3VBMDI6pi6xfiw7lr6xhDWWvQKn9udPn68kLSdY=
+github.com/multiformats/go-multiaddr v0.0.1/go.mod h1:xKVEak1K9cS1VdmPZW3LSIb6lgmoS58qz/pzqmAxV44=
+github.com/multiformats/go-multiaddr-dns v0.0.1 h1:jQt9c6tDSdQLIlBo4tXYx7QUHCPjxsB1zXcag/2S7zc=
+github.com/multiformats/go-multiaddr-dns v0.0.1/go.mod h1:9kWcqw/Pj6FwxAwW38n/9403szc57zJPs45fmnznu3Q=
+github.com/multiformats/go-multihash v0.0.1 h1:HHwN1K12I+XllBCrqKnhX949Orn4oawPkegHMu2vDqQ=
+github.com/multiformats/go-multihash v0.0.1/go.mod h1:w/5tugSrLEbWqlcgJabL3oHFKTwfvkofsjW2Qa1ct4U=
+golang.org/x/crypto v0.0.0-20190211182817-74369b46fc67 h1:ng3VDlRp5/DHpSWl02R4rM9I+8M2rhmsuLwAMmkLQWE=
+golang.org/x/crypto v0.0.0-20190211182817-74369b46fc67/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
+golang.org/x/sys v0.0.0-20190219092855-153ac476189d h1:Z0Ahzd7HltpJtjAHHxX8QFP3j1yYgiuvjbjRzDj/KH0=
+golang.org/x/sys v0.0.0-20190219092855-153ac476189d/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=