remove dev flag from examples

[bdefore]

Fixes #191

Proposed Changes

Removed all references of :dev from examples

Description

Per #157 (comment) we shouldn't be using dev images and they're out of date.

Checklist

• Read the CONTRIBUTING document.
• Read the CODE OF CONDUCT document.
• Ensure your code follows the code style of this project.
• Ensure CI and all other PR checks are green OR
  • Code compiles correctly.
  • Created tests which fail without the change (if possible).
  • All new and existing tests passed.
• Add your changes to Unreleased section of CHANGELOG.
• Improve and update the README (if necessary).
• Ensure documentation is up-to-date. The same file will be updated in plugin index when your PR is accepted, so it will be available for end-users at http://plugins.drone.io.