Address 7 outdated npm dependencies in master branch

[micky2be]

bitHound discovered 7 outdated npm dependencies. For details go to bitHound.

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You might want to update some of your dependencies.

[bchevalier]

I think I will keep it as it is as long as Jeff is used in only one project, I dont want anything to break.

[micky2be]

I understand, some can be safely updated though, like fs-extra, async, commander.
Others more core can (should) be tested to see if it improves anything.
I recommend you to install david on your system to keep track of dependencies on any projects (npm install -g david)

[micky2be]

(PS: I created this issue also because I was testing bitHound)

[micky2be]

As a reference using npm outdated:

Package	Wanted	Latest
async	0.2.10	1.4.2
buffer-crc32	0.2.5	0.2.5
canvas	1.1.6	1.2.7
commander	2.2.0	2.8.1
fs-extra	0.8.1	0.23.1
glob	4.3.1	5.0.14
image-optim	0.3.0	0.3.0
js-beautify	1.4.2	1.5.10
node-pngquant-native	0.0.12	0.2.3