service/debugger: Fix checking for CI

.travis.yml

@@ -61,6 +61,7 @@ script: >-
       docker run \
       -v $(pwd):/delve \
       --env TRAVIS=true \
+      --env CI=true \
       --privileged i386/centos:7 \
       /bin/bash -c "set -x && \
            cd delve && \

service/debugger/debugger_unix_test.go

@@ -54,7 +54,7 @@ func TestDebugger_LaunchNoExecutablePerm(t *testing.T) {
 }
 
 func TestDebugger_LaunchWithTTY(t *testing.T) {
-	if os.Getenv("TRAVIS") == "true" {
+	if os.Getenv("CI") == "true" {
 		if _, err := exec.LookPath("lsof"); err != nil {
 			t.Skip("skipping test in CI, system does not contain lsof")
 		}