Merge dev_tmp branch and revert CI changes

[nschcolnicov]

We created a temporary dev branch to work as a dev branch during the holidays and push all of the changes there.
This branch will be reviewed and merged again in january, once everyone is back.
The ci.yml file needs to be updated so that tests now also run for the dev_tmp branch, I added a TODO to remember to revert this change once the branch is merged.
This ticket is created as a reminder of this.
FYI @grst @atrigila @alanmmobbs93 @apeltzer

[nschcolnicov]

Created PR for this: #419 so we don't forget.

Next steps are:

• Reverting changes in ci.yml
• Reviewing changelog.md file

[nschcolnicov]

Dev_tmp branch won't be merged, instead we will create separate PRs for each change. This is the summary of all the changes included in that branch:

PR	Description	Ticket	Status	Author	PR to dev
#382	Adding YAML contrasts file handling + schema validation	#405	DONE	nschcolnicov	#410
		#370	DONE	nschcolnicov	#410
#404	Implement model validation	#371	To be added into dev	alanmmobbs93	Not done yet
#412	Replcae tabulartogseachip with nf-core verison	#408	To be added into dev	nschcolnicov	Not done yet
#414	Add new local module DREAM_DIFFERENTIAL to set basics for mixed model analysis	#363	To be added into dev	alanmmobbs93	Not done yet
		#406	To be added into dev	alanmmobbs93	Not done yet
		#407	To be added into dev	alanmmobbs93	Not done yet
#416	Add parameters and random terms for local module DREAM_DIFFERENTIAL			alanmmobbs93	Not done yet

FYI @atrigila @grst @apeltzer