Adds $ to URL regex

[cuducos]

I was trying to use this code to check URLs from Brazilian Federal Revenue, but some of them had a $ in the URL, e.g.: http://200.152.38.155/CNPJ/F.K03200$Z.D10510.MUNICCSV.zip (source).

This was a bug for verify-links:

$ go run main.go /tmp/urls.txt
Found 38 URIs
[200] http://200.152.38.155/CNPJ/K3241.K03200Y0.D10510.EMPRECSV.zip
[200] http://200.152.38.155/CNPJ/K3241.K03200Y4.D10510.ESTABELE.zip
[200] http://200.152.38.155/CNPJ/K3241.K03200Y4.D10510.SOCIOCSV.zip
[200] http://200.152.38.155/CNPJ/K3241.K03200Y8.D10510.SOCIOCSV.zip
[200] http://200.152.38.155/CNPJ/K3241.K03200Y0.D10510.SOCIOCSV.zip
[404] http://200.152.38.155/CNPJ/F.K03200
…

(This last line was cut just at the $.)

I suggest we add $ to the URL regex, which made this bug go away in this specific use case : )

[ellisonleao]

thanks!