Add DNS provider for Internet.bs

[ldez]

• have a homogeneous design with the other providers
• pass the linter
• do go mod tidy
• add tests (units)
• add tests ("live")
• add a provider descriptor
• generate CLI help, documentation, and readme.
• be able to do: (and put the output of this command to a comment)

rm -rf .lego

INTERNET_BS_API_KEY=xxx INTERNET_BS_PASSWORD=yyy ./lego -m your_email@example.com --dns internetbs -d *.example.com -d example.com -s https://acme-staging-v02.api.letsencrypt.org/directory run

Note the wildcard domain is important.

@bg-master could you test by running the previous command (you have to use a real domain and email)?

Closes #1430

[bg-master]

Running:

$ rm -rf .lego
$ INTERNET_BS_API_KEY=xxx INTERNET_BS_PASSWORD=yyy ./lego -m your@email.com --dns internetbs -d *.example.com -d example.com -s https://acme-staging-v02.api.letsencrypt.org/directory run
2021/06/13 02:42:45 No key found for account your@email.com. Generating a P256 key.
2021/06/13 02:42:45 Saved key to /home/me/lego/dist/.lego/accounts/acme-staging-v02.api.letsencrypt.org/your@email.com.key/keys/your@email.com.key
2021/06/13 02:42:45 Please review the TOS at https://letsencrypt.org/documents/LE-SA-v1.2-November-15-2017.pdf
Do you accept the TOS? Y/n
y
2021/06/13 02:42:53 [INFO] acme: Registering account for your@email.com
!!!! HEADS UP !!!!

Your account credentials have been saved in your Let's Encrypt
configuration directory at "/home/me/lego/dist/.lego/accounts".

You should make a secure backup of this folder now. This
configuration directory will also contain certificates and
private keys obtained from Let's Encrypt so making regular
backups of this folder is ideal.
2021/06/13 02:42:54 [INFO] [*.example.com, example.com] acme: Obtaining bundled SAN certificate
2021/06/13 02:42:54 [INFO] [*.example.com] AuthURL: https://acme-staging-v02.api.letsencrypt.org/acme/authz-v3/xxxxxxxx
2021/06/13 02:42:54 [INFO] [example.com] AuthURL: https://acme-staging-v02.api.letsencrypt.org/acme/authz-v3/xxxxxxxx
2021/06/13 02:42:54 [INFO] [*.example.com] acme: use dns-01 solver
2021/06/13 02:42:54 [INFO] [example.com] acme: Could not find solver for: tls-alpn-01
2021/06/13 02:42:54 [INFO] [example.com] acme: Could not find solver for: http-01
2021/06/13 02:42:54 [INFO] [example.com] acme: use dns-01 solver
2021/06/13 02:42:54 [INFO] [*.example.com] acme: Preparing to solve DNS-01
2021/06/13 02:42:55 [INFO] [example.com] acme: Preparing to solve DNS-01
2021/06/13 02:42:55 [INFO] [*.example.com] acme: Trying to solve DNS-01
2021/06/13 02:42:55 [INFO] [*.example.com] acme: Checking DNS record propagation using [127.0.0.53:53]
2021/06/13 02:42:57 [INFO] Wait for propagation [timeout: 1m0s, interval: 2s]
2021/06/13 02:42:57 [INFO] [*.example.com] acme: Waiting for DNS record propagation.
2021/06/13 02:43:05 [INFO] [*.example.com] The server validated our request
2021/06/13 02:43:05 [INFO] [example.com] acme: Trying to solve DNS-01
2021/06/13 02:43:05 [INFO] [example.com] acme: Checking DNS record propagation using [127.0.0.53:53]
2021/06/13 02:43:07 [INFO] Wait for propagation [timeout: 1m0s, interval: 2s]
2021/06/13 02:43:15 [INFO] [example.com] The server validated our request
2021/06/13 02:43:15 [INFO] [*.example.com] acme: Cleaning DNS-01 challenge
2021/06/13 02:43:15 [INFO] [example.com] acme: Cleaning DNS-01 challenge
2021/06/13 02:43:16 [INFO] [*.example.com, example.com] acme: Validations succeeded; requesting certificates
2021/06/13 02:43:16 [INFO] [*.example.com] Server responded with a certificate.