Round Total Hours sum to 2 decimal precision.

[adunkman]

Fixes #848.

We shouldn’t need anything more than 2 digits of decimal precision to calculate Total Hours. This fixes common floating point precision issues in JavaScript, most easily seen by adding 0.2 + 0.2 + 0.2 (which should result in 0.6, as shown below, but results in 0.6000000000000001 without rounding.

This is my first time contributing to a python project, so I’m unsure of how to write a test to cover this — let me know how, and I’d be more than happy to add (pun intended) one!

[tbaxter-18f]

Thanks for this, @adunkman, and for finding the bug in the first place.

As far as I know, there aren't currently JS tests in Tock. So, if you'd like to spearhead adding those, I think we could use the help.

[rogeruiz]

Thanks @adunkman. Writing tests for the JS in this project would require that the JavaScript be extracted outside of the HTML templates and loaded on the page as a file. Then we could have unit tests test this JS code separate of any python code.

Most of the JS in this project has been added quickly and to HTML templates. We don’t have an asset management system for external JS in the project. But this would require a refactor of most of the HTML pages among other things. Since Tock isn’t a billable project, this is probably just a good idea that may never get implemented.