[Swift4] Use CodeableHelper's dateformatter in encode() if configured

[manhhavu]

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Description of the PR

Update Swift4's CodeableHelper to use configured dateformatter in encode() method, the same as its decode().

Opened issue: #982

@jgavris (2017/07) @ehyche (2017/08) @Edubits (2017/09) @jaz-ah (2017/09) @d-date (2018/03)

[d-date]

Nice catch! 😊

[wing328]

Thanks for the PR but your commit (as shown in the Commits tab) is not linked to your Github account, which means this PR won't count as your contribution in https://github.com/OpenAPITools/openapi-generator/graphs/contributors.

Let me know if you need help fixing it.

Ref: https://github.com/OpenAPITools/openapi-generator/wiki/FAQ#how-can-i-update-commits-that-are-not-linked-to-my-github-account

[manhhavu]

@wing328 : Thanks for the suggestion. I've added the email I used for PR as my secondary email in my Github account (as suggested in the FAQ). Let me know if there are any other issues.

[wing328]

My local test result looks good

[wing328]

Here is the test result:

▸ Test execute Succeeded
All tests
Test Suite SwaggerClientTests.xctest started
PetAPITests
    ✓ test1CreatePet (2.201 seconds)
    ✓ test2GetPet (0.525 seconds)
    ✓ test3DeletePet (0.587 seconds)
StoreAPITests
    ✓ test1PlaceOrder (0.687 seconds)
    ✓ test2GetOrder (0.557 seconds)
    ✓ test3DeleteOrder (0.764 seconds)
    ✓ testDownloadProgress (0.497 seconds)
UserAPITests
    ✓ testLogin (0.464 seconds)
    ✓ testLogout (0.448 seconds)
    ✓ testPathParamsAreEscaped (0.000 seconds)

[wing328]

@manhhavu thanks again for the PR, which is included in the v3.3.0 minor release: https://twitter.com/oas_generator/status/1046941449609068544