Change all sample-generators for typescript-angular2-* to use YAML

[ePaul]

PR checklist

• Read the contribution guidelines.
• Ran the shell/batch script under ./bin/ to update Petstore sample so that CIs can verify the change. → bin/typescript-angular2-petstore*.sh (see below)
• Filed the PR against the correct branch: master for non-breaking changes.

Description of the PR

No functional changes, just different options for sample generation scripts.

There were several scripts generating samples in samples/client/petstore/typescript-angular2/*:

• bin/typescript-angular2-petstore-all.sh
  • used petstore.yaml for default + NPM, petstore.json for interfaces
• bin/typescript-angular2-petstore-interfaces.sh
  • used petstore.json
• bin/typescript-angular2-petstore-with-npm.sh
  • used petstore.json
• bin/typescript-angular2-petstore.sh
  • used petstore.json

Depending on whether you ran the -all script or the individual ones (or if both, depending on the order), you got different results, leading to spurious changes in diffs.

As the most recent change of yaml/json in those files was json → yaml in 1fc969b, I chose to use YAML for the new coherent source. (It also seems to agree with the current state of the samples in master for default+NPM, though of course not for -interfaces).

Now running either of the scripts last doesn't change anything in the generated samples.