Remove unnecessary imports update thermal module tests

[samaloney]

• Remove imports
• Updated test to use code under correct module

[KriSun95]

Would it be appropriate to also remove the import lines in sunkit-spex/sunkit_spex/legacy/fitting/init.py (the imports causing the error Iain showed) in this PR?

I'm more than happy to fork your (@samaloney) bugfix-imports-thermal-tests branch to do this and contribute here but I want to check if you would rather the other import issue to be solved separately.

[samaloney]

@KriSun95 sounds good but you should now be able to modify this PR without making another fork

git remote add samaloney https://github.com/samaloney/sunkit-spex.git
git fetch samaloney
git checkout

do stuff

git add -u
git commit
git push samaloney bugfix-imports-thermal-tests

[KriSun95]

Fantastic! I will do this shortly when I get the chance. Thanks for taking the time to show the commands I need as well!

[KriSun95]

I also ran tox to build the documentation and the example gallery seems OK (despite the fact I need to go in and fix the NuSTAR one) so removing the imports doesn't seem to have broken anything.