Dummy tidal heating

[nichollsh]

Adds a module for dummy tidal heating. This is implemented by simply allowing the user to set the tidal power density H_tide in the configuration file. Closes #190.

This required the following changes:

• Update radiative equilibrium criterion to account for the interior heat flux F_tide and F_radio. This is because global energy balance is now achieved when $F_{\text{atm}}=F_{\text{tide}}+F_{\text{radio}}$ not when $F_{\text{atm}}=0$, since $F_{\text{tide}}+F_{\text{radio}}$ effectively acts like an $F_{\text{eff}}$ (cf. hot jupiter atmosphere models).
• Add relative tolerance parameter to radeqm stop condition, rather than just an absolute tolerance (which was called F_crit). See https://web.mit.edu/10.001/Web/Tips/Converge.htm
• Update plots to include tidal and radiogenic heat fluxes. The radiogenic heating isn't new physics - PROTEUS is just now storing what SPIDER was already calculating.
• Update configuration files with new parameters.

This also lays the groundwork for implementing a new comprehensive tidal heating and orbital evolution calculation. It's not clear how these other models would operate, but they would at least have to communicate some information relating to tidal heating to the interior models.

Minor things:

• Add apt-get update to Ubuntu workflow, following this issue: Installing libcurl4-openssl-dev fails actions/runner-images#5470 (comment).

[nichollsh]

You can see the impact of the tidal heating here. The case with 10x stronger heating reaches energy balance with a surface temperature ~300 K hotter. For TRAPPIST-1b, this paper predicts Htidal in excess of 16 nW/kg.

[timlichtenberg]

Do you want me or someone else to review this already?

[nichollsh]

@timlichtenberg yes I think this is ready for review now that the tests are passing. If could please have a look at it, then that would be great.

[timlichtenberg]

This is in W m-2 as well,right?

[timlichtenberg]

Looks good, my only question is whether to include actual values also for radiogenic heating in the cfg files now or in a follow-up PR.