Update Travis CI to use standard test script and go 1.9.x.

This also switches from goveralls to codecov.

.travis.yml

@@ -5,16 +5,13 @@ os:
 language: go
 
 go:
-    - 1.7
-
-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:

codecov.yml

@@ -0,0 +1,3 @@
+coverage:
+  range: "50...100"
+comment: off