TLD list testing added

[aviiciii]

The TLD in the domain validator are checked against a valid list of TLDs from "https://data.iana.org/TLD/tlds-alpha-by-domain.txt"

This pull request solves #198

[aviiciii]

The tests on urls.py seems to fail. I'm not sure if changes on domain.py affect the latter.

Also, the domain validator depends on the internet to fetch the list of TLDs, Do we need to have a static list in case the data can't be pulled?

[nandgator]

The tests on urls.py seems to fail. I'm not sure if changes on domain.py affect the latter.

Yes, URLs are composed of either ip-address or domain.

Also, the domain validator depends on the internet to fetch the list of TLDs, Do we need to have a static list in case the data can't be pulled?

I'd prefer caching TLDs.

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For now, I'll put this PR on hold, because:

1. It introduces an external dependency (which in this case, it can be resolved fairly easily)
2. Needs a bit of complex approach (like caching)
3. The PR seeks to address issues mentioned in Why msn.comm validates? #67 & invalid email addresses but validators return True #28 (comment) which is more like answering the question "Does this flower exists today?" than answering "Is that a flower?". The former is a bit more nuanced.
4. I'm working on a couple of core changes that would effect every upcoming PR.

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Feel free to work on 1 & 2 if you like, keeping in mind that 4 could require a drastic change in this PR.

[aviiciii]

Ok cool, let me look what I can do on 1 and 2

[nandgator]

Ok cool, let me look what I can do on 1 and 2

1. You can use Python's standard library to send request.
2. Look into caching in Python.

[davidt99]

Just want to bring the attention to this library that already handle this, maybe we can use it or take inspiration:
https://github.com/john-kurkowski/tldextract