lib/npm.js
function installVer(name, ver, dir) {
        var _child$spawnSync2 = _child_process2['default'].spawnSync(npmCommand, ['install', name + '@' + ver], { cwd: dir });

        var error = _child$spawnSync2.error;

        if (error) throw error;
    }
function installVer(name, ver, dir) {
        var _child$spawnSync2 = _child_process2['default'].spawnSync(npmCommand, ['install', name + '@' + ver], { cwd: dir });

        var error = _child$spawnSync2.error;

        if (error) throw error;
    }
function installVer ( name , ver , dir ) { var _child$spawnSync2 = _child_process2 [ 'default' ] . spawnSync ( npmCommand , [ 'install' , name + '@' + ver ] , { cwd : dir } ) ; var error = _child$spawnSync2 . error ; if ( error ) throw error ; }
install package via npm

@param {String} [name] published package name
@param {String} [ver] install version
@param {String} [dir] install directory
@public
install package via npm