Remove last vestige of Travis CI

- Set a 'CI' env var when running on GitHub actions, and use this to create txt codenarc reports.
- Remove some special handling for Travis that is not required on GitHub actions.
- Remove the Travis status flag from README.

.github/workflows/testing.yml

@@ -11,6 +11,7 @@ permissions:
 
 env:
     GRADLE_OPTS: "-Xms128m"
+    CI: true
 
 jobs:
   build:

README.md

@@ -1,7 +1,7 @@
 :exclamation: Please [read release notes](https://github.com/google/protobuf-gradle-plugin/releases)
 before upgrading the plugin, as usage or compatibility requirements may change.
 
-# Protobuf Plugin for Gradle [![Status](https://travis-ci.org/google/protobuf-gradle-plugin.svg?branch=master)](https://travis-ci.org/google/protobuf-gradle-plugin)
+# Protobuf Plugin for Gradle
 The Gradle plugin that compiles Protocol Buffer (aka. Protobuf) definition
 files (``*.proto``) in your project. There are two pieces of its job:
  1. It assembles the Protobuf Compiler (``protoc``) command line and uses it to

build.gradle

@@ -169,34 +169,10 @@ tasks.create("checkJavaVersion").doLast {
 }
 [uploadArchives, publishPlugins]*.dependsOn checkJavaVersion
 
-if (System.env.TRAVIS == 'true') {
+if (System.env.CI == 'true') {
   // Normally html output is more user friendly,
-  // but we want a console printable file for Travis logs
+  // but we want a console printable file for CI logs
   project.codenarc.reportFormat = 'text'
-
-  // To limit the memory usage when running in Travis.
-  // Travis tend to kill tasks that use too much memory.
-  allprojects {
-    tasks.withType(GroovyCompile) {
-      groovyOptions.fork = false
-    }
-    tasks.withType(Test) {
-      // containers (currently) have 2 dedicated cores and 4GB of memory
-      maxParallelForks = 2
-      minHeapSize = '128m'
-    }
-  }
-  // The Android test takes longer than 10 minutes.  Travis kills the test if it has
-  // seen no output for 10 minutes, so we need to produced output.
-  test {
-    testLogging {
-      showStandardStreams = true
-      exceptionFormat = 'full'
-      showExceptions true
-      showCauses true
-      showStackTraces true
-    }
-  }
 }
 
 // Required in order to support building a mixed kotlin/groovy project. With out this,

src/test/groovy/com/google/protobuf/gradle/ProtobufPluginTestHelper.groovy

@@ -39,7 +39,7 @@ final class ProtobufPluginTestHelper {
       localBuildCache.deleteDir()
     }
     List<String> args = arguments.toList()
-    // set android build cache to avoid using home directory on travis CI.
+    // set android build cache to avoid using home directory on CI.
     args.add("-Pandroid.buildCacheDir=$localBuildCache".toString())
     args.add(fullPathTask)
     args.add("--stacktrace")