Let Bref Cloud find the error of a failed serverless deploy

[mnapoli]

When serverless deploy fails, the CLI no longer looks for the error in the osls output. It sends no error message, and Bref Cloud finds the error in the deployment logs, which already contain the whole osls output.

Bref Cloud must be deployed first: with the current Bref Cloud, failed deployments would have no error message.

Why

The CLI sent the line that follows Error:, which is often not the useful one:

• For a CloudFormation failure, it is CREATE_FAILED: HelloLambdaFunction (AWS::Lambda::Function), and AWS's reason is on the next line.
• For an unresolved variable, it is Cannot resolve serverless.yml: Variables resolution errored with:, and the variable is on the next line.

Bref Cloud can be fixed without a CLI release, and the change reaches every CLI version: it replaces the line older CLIs send with the whole error.

Also removed

The check for a missing npx never matched: it looked for npo: command not found. Bref Cloud now adds that hint from the logs. It matches the shell errors of bash (npx: command not found) and dash/busybox (npx: not found).

Tested

Tested against Bref Cloud with the server side of this change:

• An unresolved variable prints the whole osls error, with this branch and with the current release:

  Serverless Framework error: Cannot resolve serverless.yml: Variables resolution errored with:
    - Cannot resolve variable at "provider.environment.API_KEY": Value not found at "env" source
  

• Without npx in the PATH:

  The "serverless deploy" command failed: see the deployment logs.
  
  NPM is not installed: deploying a serverless.yml application requires Node.js and NPM. Install them: https://docs.npmjs.com/downloading-and-installing-node-js-and-npm