Add group-3 in Vagrantfile definitions (elastic#420)

This commit adds group-3 to the default scripts created by the
Vagrantfile that help testing nightly/release benchmarks.

This was missing from elastic#418.

Author: dliappis

night_rally/fixtures/ansible/Vagrantfile

@@ -179,14 +179,16 @@ def install_night_rally_test_script(base_ip, target_node_ip_addresses)
     # release-license is basic just because it's the default option in the JJB dropdown; ignored in nightly mode but used to copy the results as master in release charts
     night_rally --target-host="${TARGET_HOSTS}" --race-configs="resources/race-configs-group-1.json" --effective-start-date="" --mode="nightly" --version="master" --release-license="basic" --release-x-pack-components="" --runtime-jdk="bundled"
     night_rally --target-host="${TARGET_HOSTS}" --race-configs="resources/race-configs-group-2.json" --effective-start-date="" --mode="nightly" --version="master" --release-license="basic" --release-x-pack-components="" --runtime-jdk="bundled"
+    night_rally --target-host="${TARGET_HOSTS}" --race-configs="resources/race-configs-group-3.json" --effective-start-date="" --mode="nightly" --version="master" --release-license="basic" --release-x-pack-components="" --runtime-jdk="bundled"
     EOF2
 
     cat >/var/lib/jenkins/test_release.sh <<"EOF2"
     #!/usr/bin/env bash
     set -eo pipefail
     source /var/lib/jenkins/env_test_script
-    night_rally --target-host="${TARGET_HOSTS}" --race-configs="resources/race-configs-group-1.json" --effective-start-date="" --mode="release" --version="6.8.7" --release-license="basic" --release-x-pack-components="" --runtime-jdk="15"
-    night_rally --target-host="${TARGET_HOSTS}" --race-configs="resources/race-configs-group-2.json" --effective-start-date="" --mode="release" --version="6.8.7" --release-license="basic" --release-x-pack-components="" --runtime-jdk="15"
+    night_rally --target-host="${TARGET_HOSTS}" --race-configs="resources/race-configs-group-1.json" --effective-start-date="" --mode="release" --version="7.12.0" --release-license="basic" --release-x-pack-components="" --runtime-jdk="bundled"
+    night_rally --target-host="${TARGET_HOSTS}" --race-configs="resources/race-configs-group-2.json" --effective-start-date="" --mode="release" --version="7.12.0" --release-license="basic" --release-x-pack-components="" --runtime-jdk="bundled"
+    night_rally --target-host="${TARGET_HOSTS}" --race-configs="resources/race-configs-group-3.json" --effective-start-date="" --mode="release" --version="7.12.0" --release-license="basic" --release-x-pack-components="" --runtime-jdk="bundled"
     EOF2
 
     chown jenkins:jenkins /var/lib/jenkins/test_*.sh