careful treatment of string PHPExcel in migrator

[blunket]

Fixes #598

This is:

• a bugfix
• a new feature

Checklist:

• Changes are covered by unit tests
• Code style is respected
• Commit message explains why the change is made (see https://github.com/erlang/otp/wiki/Writing-good-commit-messages)
• CHANGELOG.md contains a short summary of the change
• Documentation is updated as necessary

Why this change is needed?

This PR resolves #598 by using a stricter regex when replacing the plain string 'PHPExcel' in the migration tool.

[blunket]

I truly don't understand why the build failed, but I'm open to make any changes as necessary.

[artrz]

The removed line before continue has to be there, it's part of the code style rules. Run the fixer locally.

[blunket]

Thank you very much @Arturock , I should've known.

[artrz]

You're welcome!

[blunket]

Hey @PowerKiKi , just wondering if you think this looks good or if you'd like any changes. 🙂 Also wondering, whenever you merge this, will you possibly be making a new release shortly after on composer? Thanks 😄

[PowerKiKi]

merged, thanks ! I'll release a version soon