Also ignore additional tempfiles created by the biblatex package.

Refer to the biblatex manual at http://ctan.unsw.edu.au/macros/latex/contrib/biblatex/doc/biblatex.pdf:

(p.106): The name of the additional aux files is the base name of the main input file with the string -blx and a running number appended at the end.
[...]
Apart from these aux files, biblatex uses an additional bib file with the same suffix to pass certain control parameters to BibTeX.
[...]
When using Biber, biblatex writes a control file named example.bcf and ignores \blxauxsuffix.

Note: the running number mentioned in the documentation is not always added to the suffix.

LaTeX.gitignore

@@ -3,7 +3,10 @@
 *.alg
 *.aux
 *.bbl
+*.bcf
 *.blg
+*-blx.aux
+*-blx.bib
 *.dvi
 *.fdb_latexmk
 *.fls