fix save_and_serialize.ipynb

[beginner30]

duplicated word "for Sequential models" in sentence

[tfdocsbot]

Preview and run these notebook edits with Google Colab:

• site/en/guide/keras/save_and_serialize.ipynb

Notebook diffs available on ReviewNB.com.

[googlebot]

We found a Contributor License Agreement for you (the sender of this pull request), but were unable to find agreements for all the commit author(s) or Co-authors. If you authored these, maybe you used a different email address in the git commits than was used to sign the CLA (login here to double check)? If these were authored by someone else, then they will need to sign a CLA as well, and confirm that they're okay with these being contributed to Google.
In order to pass this check, please resolve this problem and then comment @googlebot I fixed it.. If the bot doesn't comment, it means it doesn't think anything has changed.

ℹ️ Googlers: Go here for more info.

[beginner30]

@googlebot I fixed it.

[googlebot]

All (the pull request submitter and all commit authors) CLAs are signed, but one or more commits were authored or co-authored by someone other than the pull request submitter.

We need to confirm that all authors are ok with their commits being contributed to this project. Please have them confirm that by leaving a comment that contains only @googlebot I consent. in this pull request.

Note to project maintainer: There may be cases where the author cannot leave a comment, or the comment is not properly detected as consent. In those cases, you can manually confirm consent of the commit author(s), and set the cla label to yes (if enabled on your project).

ℹ️ Googlers: Go here for more info.

[beginner30]

@googlebot I consent.

[beginner30]

I checked CLA is proved, but still no cla label.
If i missed something, please comment.

[MarkDaoust]

Hi @beginner30,

Usually when the bot does this it's because the email address in the commits is not the same as the email address on the github account.

Check your $ git config user.email, and be sure you have the same one set in your github account settings.

Use $ git config --global user.email johndoe@example.com to set it.

See this article for more about how these commands work: https://git-scm.com/book/en/v2/Getting-Started-First-Time-Git-Setup