Remove TravisCI config

.travis.yml

@@ -1,29 +0,0 @@
-language: go
-
-os:
-  - linux
-  - osx
-
-go:
-  - 1.9.x
-  - 1.10.x
-  - 1.11.x
-  - 1.12.x
-  - 1.13.x
-  - tip
-
-matrix:
-  allow_failures:
-    - go: tip
-
-before_install:
-  - if [[ $TRAVIS_GO_VERSION == 1.13* ]]; then go get github.com/axw/gocov/gocov github.com/modocache/gover github.com/mattn/goveralls; fi
-
-script:
-  - go test -v -tags ci ./...
-  - if [[ $TRAVIS_GO_VERSION == 1.13* ]]; then $GOPATH/bin/goveralls -service=travis-ci; fi
-
-notifications:
-  email:
-    on_success: change
-    on_failure: always