Changed behaviour of centroid_peaks when y1==y3.
Fixed issue #22 and maybe issue #20 (to be verified).
Sometimes, a centered peak was misplaced with an erroneous signal.
This was caused by applying the gauss fit to a section where there was no
peak.
This could add a few peaks when applying the centroid_peaks
function.

Signed-off-by: Pier-Luc Plante <pier-luc.plante.1@ulaval.ca>
Fixed the centroid function bug.
The last commit only fixed a few cases.
This should fix a few more.

Signed-off-by: Pier-Luc Plante <pier-luc.plante.1@ulaval.ca>
Fixed the conditions for applying gauss fit.

Signed-off-by: Pier-Luc Plante <pier-luc.plante.1@ulaval.ca>
Merge pull request #24 from plpla/master

Centroid_peaks now applied correctly