No longer preserves permissions with v0.11.0

[Tarang]

If a npm module has a file in it, node-lambda wont preserve these permissions when uploading files.

Reproduction:

Have a file in a project with 0755 permissions create a deployment (fetch from lambda)/zip file

Results:

Version 0.10.0 (installed with npm install node-lambda@0.10.0 -g has the correct permissions (0755)
Version 0.11.0 has the incorrect permissions (0664)

End result:

Projects with binary files will have EACCS errors while running spawn to a child process, which is unexpected.

[abetomo]

Please wait for about three days as I will check and respond.
(If there is someone who can respond more quickly, please take measures.)

[bluepeter]

Experiencing this problem too trying to spawn a phantomjs process.

[abetomo]

I fixed bugs and opened PR. #335