Bump a package version
# version 1.0.0
$ npm version major # 2.0.0
$ npm version premajor # 2.0.0-0
# version 1.0.0
$ npm version minor # 1.1.0
$ npm version preminor # 1.1.0-0
# version 1.0.0
$ npm version patch # 1.0.1
$ npm version prepatch # 1.0.1-0
# version 1.0.0-0
$ npm version prerelease # 1.0.0-1
# version 1.0.0
$ npm version 3.2.1 # 3.2.1