Missing check to ensure callback exists in tag.js

[nijikokun]

Missing check to ensure callback exists in tag.js

[nijikokun]

Adding a callback makes any pipe afterwards subsequently throw that pipe is undefined on childprocess.

[nijikokun]

Instead of using the through2 push command in this repository instead just used exec to push and it works fine within the tag callback.

[stephenlacy]

Could you show an example of your code issue?

[joshuaali]

A simple call to git.tag(version, message) without passing in a callback is enough to replicate this issue.