Ifermi

New features:

- Support for plotting individual bands. Specified using the `--plot-index` command
line option. (aj-searle)

Enhancements:

- Fixed high-symmetry points markers.
- Updated dependencies.

Bug fixes:

- Fixed serialization issues.

Bug fixes:

- Better handling of integer decimation factors.

Enhancements:

- Added function to trim band structure to within a energy cutoff.
- Improved decimation options.

Publish IFermi on zenodo.

Saving interactive html plots is now possible using the plotly backend with:
`ifermi plot --output filename.html`.