Update plugin version to 2.7.0 (WordPress#6256)

* Update plugin version to 2.7.0

* Element: Remove deprecated getWrapperDisplayName

Update plugin version to 2.6.0. (WordPress#6016)

Merge pull request WordPress#5853 from WordPress/update/v-2-5-0

Update plugin version to 2.5

Merge pull request WordPress#5616 from WordPress/replace/shallow-equal

Framework: Replace is-equal-shallow with shallowequal

Merge pull request WordPress#5336 from WordPress/update/v-2-3-0

Update plugin version to 2.3.0.

Update version to 2.2.0. (WordPress#5108)

Update version to 2.1.0. (WordPress#4677)

Merge pull request WordPress#4429 from WordPress/fix/gutenberg-activa…

…tion-undefined-constant-warning

Fix warning plugin activation

Update plugin version to 1.9.1

Update version to 1.9.0. (WordPress#3874)