added aws_access_key and aws_secret_key aliases to ec2_group arguments

cloud/ec2_group

@@ -42,13 +42,13 @@ options:
       - EC2 secret key
     required: false
     default: null
-    aliases: []
+    aliases: ['aws_secret_key']
   ec2_access_key:
     description:
       - EC2 access key
     required: false
     default: null
-    aliases: []
+    aliases: ['aws_access_key']
   state:
     version_added: "1.4"
     description:
@@ -110,8 +110,8 @@ def main():
             vpc_id=dict(),
             rules=dict(),
             ec2_url=dict(aliases=['EC2_URL']),
-            ec2_secret_key=dict(aliases=['EC2_SECRET_KEY'], no_log=True),
+            ec2_secret_key=dict(aliases=['EC2_SECRET_KEY', 'aws_secret_key'], no_log=True),
-            ec2_access_key=dict(aliases=['EC2_ACCESS_KEY']),
+            ec2_access_key=dict(aliases=['EC2_ACCESS_KEY', 'aws_access_key']),
             region=dict(choices=['eu-west-1', 'sa-east-1', 'us-east-1', 'ap-northeast-1', 'us-west-2', 'us-west-1', 'ap-southeast-1', 'ap-southeast-2']),
             state = dict(default='present', choices=['present', 'absent']),
         ),