Tests: Fixing AsciiDoctor-revealjs test

Signed-off-by: Damien DUPORTAL <[email protected]>

tests/test_suite.bats

@@ -34,7 +34,7 @@ teardown() {
 }
 
 @test "asciidoctor-revealjs is callable without error" {
-  docker run -t --rm "${DOCKER_IMAGE_NAME}" asciidoctor-revealjs -v
+  docker run -t --rm "${DOCKER_IMAGE_NAME_TO_TEST}" asciidoctor-revealjs -v
 }
 
 @test "make is installed and in the path" {