title: boto3 : AttributeError: 'EC2' object has no attribute 'create_instances'
body: <pre><code>client = boto3.client('ec2', 
          aws_access_key_id=key,
          aws_secret_access_key=secret,
          region_name='ap-southeast-1')
  
  
      response = client.create_instances(
          DryRun=True,
          ImageId=ami1,
          MinCount=1,
          MaxCount=1,
          KeyName='my-key',
          SecurityGroupIds=[sg1, sg2],
          InstanceType='m3.medium',
          Placement={
              'AvailabilityZone': 'ap-southeast-1a'
          },
          SubnetId=sb1,
          NetworkInterfaces=[
              {
                  'NetworkInterfaceId': vpc1,
                  'SubnetId': sb1,
                  'Description': 'Description'
              }
          ]
      )
      print response 
  </code></pre>
  
  <p>getting error while making api call to create instance, I have verified other operation like describe_images is working fine so keys are proper.</p>
  
  <p>am I missing something ?</p>