[travis] test multiple packages

.travis.yml

@@ -8,9 +8,7 @@ before_install:
   - go get -u -t ./...
 
 script:
-  - go test -v -race -coverprofile=coverage.txt -covermode=atomic
+  - ./test.sh
 
 after_success:
   - bash <(curl -s https://codecov.io/bash)
-
-comment: off

test.sh

@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+
+set -e
+echo "" > coverage.txt
+
+for d in $(go list ./... | grep -v vendor); do
+    go test -v -race -coverprofile=profile.out -covermode=atomic $d
+    if [ -f profile.out ]; then
+        cat profile.out >> coverage.txt
+        rm profile.out
+    fi
+done