regression: CLI processing of globs

The prior version of HTTPSnippet allowed processing of globs on the CLI as follows:

httpsnippet ./*.json --target node --client request --output ./snippets

$ tree snippets/
snippets/
├── endpoint-1.js
├── endpoint-2.js
└── endpoint-3.js

I wasn't aware of this prior functionality (and there were no tests covering it) so it was missed.

Shouldn't be too terrible to add back. Let's have some tests for it this time, too.

Reproduction steps

run the following:

./bin/httpsnippet src/fixtures/requests/*.json --target node --client unirest --output ./example

And it returns this input:

Unknown arguments: src/fixtures/requests/application-json.json, src/fixtures/requests/cookies.json, src/fixtures/requests/custom-method.json, src/fixtures/requests/full.json, src/fixtures/requests/headers.json, src/fixtures/requests/https.json, src/fixtures/requests/jsonObj-multiline.json, src/fixtures/requests/jsonObj-null-value.json, src/fixtures/requests/multipart-data.json, src/fixtures/requests/multipart-file.json, src/fixtures/requests/multipart-form-data.json, src/fixtures/requests/multipart-form-data-no-params.json, src/fixtures/requests/nested.json, src/fixtures/requests/query.json, src/fixtures/requests/short.json, src/fixtures/requests/text-plain.json

When it should, instead, process all of those files.

Comienza con el punto de entrada de la CLI en bin/httpsnippet y reproduce el fallo usando el comando glob contra src/fixtures/requests/*.json. Traza cómo se analizan los argumentos y cómo se procesa una única entrada; después, añade pruebas de la CLI que cubran varios archivos obtenidos mediante glob y verifica que cada entrada produzca una salida en lugar de un error de argumentos desconocidos.