Update graham-campbell/testbench requirement from ^3.1 to ^3.1 || ^4.0

[dependabot[bot]]

Updates the requirements on graham-campbell/testbench to permit the latest version.

Release notes

Sourced from graham-campbell/testbench's releases.

V4.0 (06/08/2017)

• Support PHP 7.0, 7.1, 7.2
• Support Laravel 5.1 - 5.5
• Support PHPUnit 6
• Replaced AbstractNewTestCase

Changelog

Sourced from graham-campbell/testbench's changelog.

CHANGE LOG

V5.6 (UPCOMING)

• Support PHPUnit 10 too
• Remove app from getServiceProviderClass definition but not calls

V5.5.1 (25/07/2020)

• Corrected composer.json

V5.5 (25/07/2020)

• Provisional PHP 8.0 support
• Provisional Laravel 8 support

V5.4.2 (13/04/2020)

• Updated funding information

V5.4.1 (01/03/2020)

• Miscellaneous tweaks

V5.4 (28/12/2019)

• Added Laravel 7 support
• Support PHPUnit 9 too

V5.3.1 (28/08/2019)

• Fixed orchestral version constraint

V5.3 (26/08/2019)

• Added Laravel 6 support

V5.2.1 (30/06/2019)

• Fixes for PHPUnit 8

... (truncated)

Commits

• e643545 Released 4.0
• ab7963f Merge pull request #17 from GrahamCampbell/analysis-zGEAwr
• 2975d57 Apply fixes from StyleCI
• 29b0e31 Laravel 5.5
• b773d7b Fixes
• b251532 Fixes
• 9dc2817 Added analyzer to tests
• 900cafc Enabled strict types
• 9257c2c Clarification
• 9435667 Upgraded mockery
• Additional commits viewable in compare view

Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting @dependabot rebase.

---

Dependabot commands and options

You can trigger Dependabot actions by commenting on this PR:

• @dependabot rebase will rebase this PR
• @dependabot recreate will recreate this PR, overwriting any edits that have been made to it
• @dependabot merge will merge this PR after your CI passes on it
• @dependabot squash and merge will squash and merge this PR after your CI passes on it
• @dependabot cancel merge will cancel a previously requested merge and block automerging
• @dependabot reopen will reopen this PR if it is closed
• @dependabot close will close this PR and stop Dependabot recreating it. You can achieve the same result by closing it manually
• @dependabot ignore this major version will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself)
• @dependabot ignore this minor version will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself)
• @dependabot ignore this dependency will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)