JuliaMolSim/DFTK.jl: v0.1.6

DFTK v0.1.6 Diff since v0.1.5 Merged pull requests: Add nonvariatonal methods and total field for energies (#268) (@antoine-levitt) More helpful messages in occupation (#269) (@mfherbst) CompatHelper: bump compat for "Optim" to "0.22" (#270) (@github-actions[bot]) Polish SCF printing and automatic diagtol selection (#271) (@mfherbst) Implement HybridMixing (#272) (@mfherbst) Bugfix: apply_kernel without functionals (#273) (@mfherbst) Various small amendments (SCF printing, GGA functionals, mixing) (#275) (@mfherbst) Some more reasonable defaults for number of bands and kgrids (#276) (@mfherbst) Add example about SCF callbacks (#277) (@mfherbst) Adding H2 geometry optimzation example (#278) (@gkemlin) Correct for subtle numerical issue when finding Fermi level (#279) (@mfherbst