Update docs to check for empty object

[mikeesto]

Hi! I recently came across this project. Huge fan.

One issue that I ran into was checking if no files had been uploaded. The docs recommend if (!req.files). But as req.files has been intentionally left as an empty object to follow the same conventions of other middlewares, this if statement will never be true. The reasonable way seems to be to check if the object is empty. I've updated the docs to reflect this.

There's also some discussion about this in #31

Thanks : )

[coveralls]

Coverage remained the same at 95.536% when pulling 683c047 on MichaelE1:docs-check-empty-object into 4d911b6 on richardgirges:master.

[coveralls]

Coverage remained the same at 95.536% when pulling 683c047 on MichaelE1:docs-check-empty-object into 4d911b6 on richardgirges:master.

[coveralls]

Coverage remained the same at 95.536% when pulling 683c047 on MichaelE1:docs-check-empty-object into 4d911b6 on richardgirges:master.

[coveralls]

Coverage remained the same at 95.536% when pulling 683c047 on MichaelE1:docs-check-empty-object into 4d911b6 on richardgirges:master.

[coveralls]

Coverage remained the same at 95.536% when pulling 683c047 on MichaelE1:docs-check-empty-object into 4d911b6 on richardgirges:master.

[coveralls]

Coverage remained the same at 95.536% when pulling 683c047 on MichaelE1:docs-check-empty-object into 4d911b6 on richardgirges:master.

[richardgirges]

Hey there, GREAT catch! Thanks for sending this!!