Remove duplicate bib

[janheinrichmerker]

The entries are also present here:

ir_datasets/ir_datasets/docs/bibliography.bib

Lines 231 to 243 in f669a1c

	@inproceedings{Roberts2017TrecPm,
	title={Overview of the TREC 2017 Precision Medicine Track},
	author={Kirk Roberts and Dina Demner-Fushman and Ellen Voorhees and William R. Hersh and Steven Bedrick and Alexander J. Lazar and Shubham Pant},
	booktitle={TREC},
	year={2017}
	}
	@inproceedings{Roberts2018TrecPm,
	title={Overview of the TREC 2018 Precision Medicine Track},
	author={Kirk Roberts and Dina Demner-Fushman and Ellen Voorhees and William R. Hersh and Steven Bedrick and Alexander J. Lazar},
	booktitle={TREC},
	year={2018}
	}