Raise exception if ip_ranges or groups have duplicate values.

[satoruh]

Adding validation codes for permission.

Problem

At first, apply the following DSL.

ec2 "vpc-XXXXXXXX" do
  security_group "default" do
    description "default VPC security group"

    ingress do
      permission :tcp, 443..443 do
        ip_ranges("192.0.2.1/32")   

        groups("default")
      end 
    end 

    egress do
      permission :any do
        ip_ranges("0.0.0.0/0")   
      end 
    end 
  end 
end

And apply the following DSL.

ec2 "vpc-XXXXXXXX" do
  security_group "default" do
    description "default VPC security group"

    ingress do
      permission :tcp, 443..443 do
        ip_ranges("192.0.2.1/32", "192.0.2.1/32")   

        groups("default", "default")   
      end 
    end 

    egress do
      permission :any do
        ip_ranges("0.0.0.0/0")   
      end 
    end 
  end 
end

Then piculet shows following messages, but do nothing.

Apply `Groupfile` to SecurityGroup
Update Permission: vpc-XXXXXXXX > default(ingress) > tcp 443..443
No change

[winebarrel]

Thanks for your PR 👍

[winebarrel]

v0.2.9.beta has been released.
Please try it out. 😃