Switch from Travis CI to GitHub Actions

travis-ci.org is being shut down, so switch to GitHub Actions.

It should be mostly equivalent, but I did drop functionality in a couple
cases:

- Publishing release binaries.  I don't think providing Linux binaries
  is useful, since people build their own anyway.  So I left this out.

- Build and testing on ppc64le.  GitHub Actions only natively supports
  x86.  I tried uraimo/run-on-arch-action, which uses Docker and QEMU
  user-mode emulation, but the fscrypt tests can't be run because
  QEMU user-mode emulation doesn't support all the needed system calls.

1 files changed, 1 insertions, 1 deletions

diff --git a/README.md b/README.md
index 0fd6b24..9abaedd 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # fscrypt [![GitHub version](https://badge.fury.io/go/github.com%2Fgoogle%2Ffscrypt.svg)](https://github.com/google/fscrypt/releases)
 
-[![Build Status](https://travis-ci.org/google/fscrypt.svg?branch=master)](https://travis-ci.org/google/fscrypt)
+[![Build Status](https://github.com/google/fscrypt/workflows/ci/badge.svg)](https://github.com/google/fscrypt/actions?query=workflow%3ACI+branch%3Amaster)
 [![Coverage Status](https://coveralls.io/repos/github/google/fscrypt/badge.svg?branch=master)](https://coveralls.io/github/google/fscrypt?branch=master)
 [![GoDoc](https://godoc.org/github.com/google/fscrypt?status.svg)](https://godoc.org/github.com/google/fscrypt)
 [![Go Report Card](https://goreportcard.com/badge/github.com/google/fscrypt)](https://goreportcard.com/report/github.com/google/fscrypt)