Fix Insecure reference to JS and CSS and specify .loading tag

# What's Changed
* Made references to google location API and Fonts over HTTPS because they weren't loading on the live server (which is broken, so this should get pushed). closes #232.
* Add `loading` class to submit buttons, so that not all disabled buttons are shown as loading. 

# What's next. 
* I suspect a big next step is starting to calculate what the compatibility of a guide is according to what a user has listed in their profile.
* More tweaks to the edit functionality, though it's functional at the moment. 
* Start figuring out ways to bring in a bit more crop information.
Prefer single-quoted strings when you don't need string interpolation or special symbols.