Improvements

[eimanip]

Hi,

First of all, thanks for the great script!

I made a couple of improvements in the script. The changes are backward-compatible. Here are the changes:

• Use path.join() instead of string concatenation for making file names: Using string concatenation is unsafe. Also, it made the output file to have analytics.js path file to be like ".//analytics.js". It would fix this.
• Implement the ability to change the name of the gtag.js file name in CLI: I wanted the ability to specify a different file name for the output file instead of google-analytics-local.js
• Remove tmp directory: It's already specified in the .gitignore file, however it was included in the repo.
• Automatically make necessary directories while saving the file: Using fs.mkdir, we can make sure that the specified folder is created and exists without prior need to do create it manually.

Let me know what you think.
Thanks

P.S. I made some other changes based on this branch to be able to specify the output directory. Currently, it's writing the folder path in the script file, which is something that I don't want. Because the changes are not backward-compatible, I didn't include them in this pull request. You can find these changes here.

[scriptex]

Thanks, @eimanip ! I will take a look as soon as I can.

[scriptex]

Besides a one minor thing (yes, I know ...) everything looks good :)

[scriptex]

The improvements are available on NPM and Github 🎉