This is a Bug Report

Description

When the provider name is a variable, the proper plugin may not be used.

For bug reports:

• What went wrong?
  The loaded deploy plugin was lib/plugins/deploy.
• What did you expect should have happened?
  The loaded deploy plugin to be lib/plugins/aws/common/deploy
• What was the config you used?

---
custom:
  name: aws

provider:
  name: ${self:custom.name}
---

Similar or dependent issues:

• invoke local does not work with variable substitution in provider #4817 , Bug: Packaging fails silently when referencing external provider information #4814
  I'm assuming this is why the above issues have no "output".

Additional Data

I've noticed in PluginManager, the following snippet:

    // ignore plugins that specify a different provider than the current one
    if (pluginProvider
      && (pluginProvider !== this.serverless.service.provider.name)) {
      return;
    }

The issue is the provider variables have not been loaded by this step, so I'm assuming the aws plugins are then ignored?

• Serverless Framework Version you're using:
  1.26.0 (master branch at time of posting)
• Operating System:
  Ubuntu 16.04