getObject can throw uncaught ENOENT if object is concurrently deleted

[gabegorelick]

Relevant code from getObject:

mock-aws-s3/lib/mock.js

Lines 312 to 314 in 6b5aa02

	fs.readFile(path, function (err, data) {
	if (!err) {
	var stat = fs.statSync(path)

Ignoring the fact that this probably shouldn't be doing synchronous I/O (if not, then why isn't readFileSync being called instead of the async variant?), the issue is the underlying file may be deleted in between the readFile and statSync calls. This results in an uncaught Error: ENOENT: no such file or directory, instead of the expected NoSuchKey error being returned.