Fix TwitterAds::Creative::PromotedTweet#save (#239)

[bugcloud]

• Fix invalid converting params

Issue Type: Bug

Fixes: #239

Changes Included:

• Fix invalid converting params
• Add test code of converting params

Check List:

• [x] Includes adequate test coverage for changes made.
• [ ] Includes new or updated documentation.
• [ ] Includes new or updated usage examples.

[CLAassistant]

All committers have signed the CLA.

[tushdante]

Hey @bugcloud - Thanks for making this change. It looks like there's a couple linting errors that were detected. Could you resolve those and commit your changes?

[bugcloud]

@tushdante Thank you for replying. I fixed a lint error. https://github.com/twitterdev/twitter-ruby-ads-sdk/pull/240/commits/f64ee61bf8af645dc141e5580afa8f9d5bf3602e

Before

$ bundle exec rubocop spec/twitter-ads/creative/promoted_tweet_spec.rb
WARNING:  No private key present, creating unsigned gem.
Inspecting 1 file
C

Offenses:

spec/twitter-ads/creative/promoted_tweet_spec.rb:51:101: C: Line is too long. [165/100]
      expect(Request).to receive(:new).with(client, :post, "/#{TwitterAds::API_VERSION}/accounts/#{account.id}/promoted_tweets", expected_params).and_return(request)
                                                                                                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

1 file inspected, 1 offense detected

After

$ bundle exec rubocop
WARNING:  No private key present, creating unsigned gem.
Inspecting 103 files
.......................................................................................................

103 files inspected, no offenses detected