Don't call sys.exit in sns_topic, use HAS_BOTO to fail

lib/ansible/modules/extras/.travis.yml

@@ -16,5 +16,5 @@ script:
   - python2.4 -m compileall -fq -x 'cloud/|monitoring/zabbix.*\.py|/dnf\.py|/layman\.py|/maven_artifact\.py|clustering/(consul.*|znode)\.py|notification/pushbullet\.py' .
   - python2.6 -m compileall -fq .
   - python2.7 -m compileall -fq .
-  - ansible-validate-modules --exclude 'cloud/amazon/sns_topic\.py|cloud/centurylink/clc_aa_policy\.py|cloud/centurylink/clc_alert_policy\.py|cloud/centurylink/clc_blueprint_package\.py|cloud/centurylink/clc_firewall_policy\.py|cloud/centurylink/clc_group\.py|cloud/centurylink/clc_loadbalancer\.py|cloud/centurylink/clc_modify_server\.py|cloud/centurylink/clc_publicip\.py|cloud/centurylink/clc_server\.py|cloud/centurylink/clc_server_snapshot\.py|cloud/docker/docker_login\.py|messaging/rabbitmq_binding\.py|messaging/rabbitmq_exchange\.py|messaging/rabbitmq_queue\.py|monitoring/circonus_annotation\.py|network/snmp_facts\.py|notification/sns\.py' .
+  - ansible-validate-modules --exclude 'cloud/centurylink/clc_aa_policy\.py|cloud/centurylink/clc_alert_policy\.py|cloud/centurylink/clc_blueprint_package\.py|cloud/centurylink/clc_firewall_policy\.py|cloud/centurylink/clc_group\.py|cloud/centurylink/clc_loadbalancer\.py|cloud/centurylink/clc_modify_server\.py|cloud/centurylink/clc_publicip\.py|cloud/centurylink/clc_server\.py|cloud/centurylink/clc_server_snapshot\.py|cloud/docker/docker_login\.py|messaging/rabbitmq_binding\.py|messaging/rabbitmq_exchange\.py|messaging/rabbitmq_queue\.py|monitoring/circonus_annotation\.py|network/snmp_facts\.py|notification/sns\.py' .
   #- ./test-docs.sh extras

lib/ansible/modules/extras/cloud/amazon/sns_topic.py

@@ -134,9 +134,9 @@ import re
 try:
     import boto
     import boto.sns
+    HAS_BOTO = True
 except ImportError:
-    print "failed=True msg='boto required for this module'"
+    HAS_BOTO = False
-    sys.exit(1)
 
 
 def canonicalize_endpoint(protocol, endpoint):
@@ -186,6 +186,9 @@ def main():
 
     module = AnsibleModule(argument_spec=argument_spec, supports_check_mode=True)
 
+    if not HAS_BOTO:
+        module.fail_json(msg='boto required for this module')
+
     name = module.params.get('name')
     state = module.params.get('state')
     display_name = module.params.get('display_name')