Update Travis CI to use standard test script.

This also switches from goveralls to codecov.

.travis.yml

@@ -6,16 +6,13 @@ os:
 language: go
 
 go:
-    - 1.9
-
-install: true
+  - 1.9.x
 
 before_install:
   - make deps
 
 script:
-  - go vet
-  - $GOPATH/bin/goveralls -service="travis-ci"
+  - bash <(curl -s https://raw.githubusercontent.com/ipfs/ci-helpers/master/travis-ci/run-standard-tests.sh)
 
 cache:
     directories:

Makefile

@@ -4,11 +4,7 @@ gx:
 	go get github.com/whyrusleeping/gx
 	go get github.com/whyrusleeping/gx-go
 
-covertools:
-	go get github.com/mattn/goveralls
-	go get golang.org/x/tools/cmd/cover
-
-deps: gx covertools
+deps: gx
 	gx --verbose install --global
 	gx-go rewrite
 

codecov.yml

+coverage:
+  range: "50...100"
+comment: off