Add configuration option to disable rotating spinner

[olivierlacan]

First, thank you for this project. I discovered the page:fetch and page:load events recently and was thinking about building something similar (but not nearly as unobtrusive). This project appeared at the perfect time. 😺

It seems redundant to me to have a rotating spinner and and a loading indicator bar. If the goal is to pretend to give a real progress bar, go for it. Don't mix in a indeterminate loader at the same time.

At least it should be an option. While it's easy to integrate a thin horizontal bar with basically no design changes, the rotating spinner overlays with existing navigation elements on the app I'm using it on. And it's likely to cause similar issues with other people as well.

[rstacruz]

Hey! You can just remove the entire section from the CSS file.

(On a side note, I've found that it's best to reposition it -- try placing it next to your logo!)

[rahulcs]

@rstacruz I have added a configuration option to disable the spinner. Would you be willing to accept a PR?

[rstacruz]

How's it like?

[rahulcs]

Here's my PR: #9