*: remove mentions of Travis CI (#2014)

Signed-off-by: Simon Pasquier <spasquie@redhat.com>

.circleci/config.yml

@@ -17,8 +17,7 @@ jobs:
     - run:
         name: Remove existing Go installation
         command: sudo rm -rf /usr/local/go
-    # Whenever the Go version is updated here, .travis.yml and .promu.yml
-    # should also be updated.
+    # Whenever the Go version is updated here, .promu.yml should also be updated.
     - go/install:
         version: "1.12.9"
     - run:
@@ -38,8 +37,7 @@ jobs:
 
   test:
     docker:
-    # Whenever the Go version is updated here, .travis.yml and .promu.yml
-    # should also be updated.
+    # Whenever the Go version is updated here, .promu.yml should also be updated.
     - image: circleci/golang:1.12
     # maildev containers are for running the email tests against a "real" SMTP server.
     # See notify/email_test.go for details.

README.md

@@ -1,6 +1,5 @@
-# Alertmanager [![Build Status](https://travis-ci.org/prometheus/alertmanager.svg?branch=master)][travis]
+# Alertmanager [![CircleCI](https://circleci.com/gh/prometheus/alertmanager/tree/master.svg?style=shield)][circleci]
 
-[![CircleCI](https://circleci.com/gh/prometheus/alertmanager/tree/master.svg?style=shield)][circleci]
 [![Docker Repository on Quay](https://quay.io/repository/prometheus/alertmanager/status)][quay]
 [![Docker Pulls](https://img.shields.io/docker/pulls/prom/alertmanager.svg?maxAge=604800)][hub]
 
@@ -390,7 +389,6 @@ Refer to [ui/app/CONTRIBUTING.md](ui/app/CONTRIBUTING.md).
 ![](doc/arch.svg)
 
 
-[travis]: https://travis-ci.org/prometheus/alertmanager
 [hub]: https://hub.docker.com/r/prom/alertmanager/
 [circleci]: https://circleci.com/gh/prometheus/alertmanager
 [quay]: https://quay.io/repository/prometheus/alertmanager