.gitignore cleanup
.gitignore cleanup

Removed obsolete files/dirs
Added .coverage and covhtml
Ordered alphabetically

Change-Id: Iac10b075f318c264549ee017688eccd52deae07d

stackforge/networking-mlnx,openstack/networking-mlnx,openstack/networking-mlnx,stackforge/networking-mlnx,moshele/networking-mlnx-master,moshele/networking-mlnx