Update crawler html selector for series page

[AmirRezaM75]

This PR fixes #100 .
Algolia result is not up to date; even in main website (laracasts) you can't get any result for "code katas in phpunit" or newer course like "javascript-techniques-for-server-side-developers".
And @carlosflorencio knews about that and he was scrapping series page and merging them with algolia result in App/Laracasts/Controller.php.
But query selector is out dated. I just update crawler filtering and it works fine.

[carlosflorencio]

Thanks @AmirRezaM75, once this is tested and confirmed working by someone else I'll merge it 💪.

[willvincent]

Confirmed, this resolves this issue!

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Authenticating
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> Successfull!

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Starting Collecting the data
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Checking for options []
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> No options provided

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Downloading
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> 0 new lessons and 2 episodes. 2.917s elapsed with 6.00Mb of memory usage.

[carlosflorencio]

Thanks for testing @willvincent, awesome work @AmirRezaM75.

[AmirRezaM75]

@carlosflorencio Your welcome <3