Improve gitignore with Emacs backup files pattern.
Improve gitignore with Emacs backup files pattern.

Signed-off-by: Ilya Baryshev <e1084850662b2d900137c1be08ebc9f0ba3bbf65@gmail.com>

manish211/coveralls-python,Jwpe/coveralls-python,jvarho/coveralls-python,coagulant/coveralls-python,ionelmc/coveralls-python,jessamynsmith/coveralls-python,lolletsoc/coveralls-python,coveralls-clients/coveralls-python