remove breadcrumbs
remove breadcrumbs

Closes [issue 144](https://github.com/datacarpentry/datacarpentry.github.io/issues/144)
datacarpentry/datacarpentry.github.io,tracykteal/datacarpentry.github.io,tracykteal/datacarpentry.github.io,ErinBecker/datacarpentry.github.io,ErinBecker/datacarpentry.github.io,datacarpentry/datacarpentry.github.io,tracykteal/datacarpentry.github.io,ErinBecker/datacarpentry.github.io,ErinBecker/datacarpentry.github.io,tracykteal/datacarpentry.github.io,datacarpentry/datacarpentry.github.io