Use async features in example generator

[superkhau]

• Change app.importing to app.booting
• Use callbacks instead of emitting import done
• Replace import done event with the ready event

Connected to #74

[superkhau]

@bajtos Review please.

[bajtos]

Will this exit the process with a non-zero status code when the import fails?

[superkhau]

Yes, as long as err is returned in the callback (we throw by default in strongloop/loopback-workspace@223758f#diff-383e9ce062435fb34a4326cdf175c907R16 causing an unhandledException event causing Node to return 1 for the exit code). I did a smoke test by changing the name of the JSON file in import.js deliberately causing a missing file error then checking the exit status in bash via echo $? which returned 1.

[superkhau]

@bajtos Review please.

[bajtos]

The code LGTM. Please update the commit message before landing, "Replace import done event with the ready event" is no longer true.

[superkhau]

TY, commit message removed.

[bajtos]

Cool, please land the patch yourself. Do you have permissions to publish a new version to npmjs.org? Does this depend on a new version of loopback-workspace (see strongloop/loopback-workspace#172)? In that case we should bump up the minimum required version in package.json too.

[superkhau]

TY, yes I have publish permissions. I will bump the strongloop/loopback-workspace version and merge accordingly.