Review prospector with pyroma configuration in pre-commit

[jspaaks]

Current code is a bit of a workaround, review to see if it can be improved / be made more idiomatic.

cffconvert/.pre-commit-config.yaml

Lines 22 to 27 in 1608ab4

	# Not really the right syntax but it kinda works. It installs the dev and testing
	# dependencies from the default branch of cffconvert on GitHub in the environment
	# used by prospector
	#
	# Issue: https://github.com/citation-file-format/cffconvert/issues/325
	- "git+https://github.com/citation-file-format/cffconvert#egg=cffconvert[dev,testing]"

[jspaaks]

Refs:

• #339

Added pyroma as a direct dependency, updated the documentation with instructions on how to run it, updated pre-commit configuration to run pyroma separate from prospector.