Ensure that disabled rules don't execute while running a sls remove

[VirtualVirtuoso]

There's a bug where if you have a disabled sync rule, like so:

  s3Sync:
    - bucketName: ${self:custom.hostingBucketName}
    - bucketName: ${self:custom.storybookBucketName}
      enabled: false
      localDir: storybook-static

And you try to run sls remove, if that bucket doesn't exist in the CloudFormation stack, s3-sync throws the following error:

Error:
NoSuchBucket: The specified bucket does not exist
    at Request.extractError ([snipped]/lib/node_modules/serverless/node_modules/aws-sdk/lib/services/s3.js:715:35)
    at Request.callListeners ([snipped]/lib/node_modules/serverless/node_modules/aws-sdk/lib/sequential_executor.js:106:20)

The problem is due to the fact that in the clear command, the process doesn't exit out early if the disabled flag is set. The fix is simply to add a guard clause in the clear() function, and exit if the enabled field is false. This means s3-sync won't try to retrieve the bucket, causing the above error.

[VirtualVirtuoso]

Change here is removing some non breaking spaces someone had introduced to the README

[k1LoW]

Thank you!