Merge branch 'feature-gitignore' into 'master'

Feature gitignore

See merge request cosmotools/CAMEL!1

.gitignore

+/cmt/Makefile
+/cmt/cleanup.csh
+/cmt/cleanup.sh
+/cmt/requirements
+/cmt/setup.csh
+/cmt/setup.sh
+/lik/camel_data
+/lik/planck_data
+/src/class_extra/spectra_extra.ph
+/src/ini.pp
+/src/spectra_extra.pp
+/Linux-x86_64/