Travis-CI configuration added. Now, we'll test coverage on every commit.

.travis.yml

@@ -0,0 +1,14 @@
+language: go
+
+go:
+  - 1.12.x
+  - tip
+
+before_install:
+  - go get -t -v ./...
+
+script:
+  - go test -race -coverprofile=coverage.txt -covermode=atomic
+
+after_success:
+  - bash <(curl -s https://codecov.io/bash)