Remove prepublish build as it is executed also at npm install

[jpetitcolas]

From #122 (comment):

One thing is that when we install event drops(npm install) it automatically run's make build.
1.how do you achieve that? I didn't saw that anywhere in the code or in the package.json scripts.
2.Can we disable that . this is very annoying for windows users that does not have make (I don't think that this is required process since windows users can run this with webpack

We should remove the prepublish hook and instead prepare a make publish target.