upgrade gemfile

Signed-off-by: Sebastien Varrette <sebastien.varrette@uni.lu>
bump to version '0.1.2'

Signed-off-by: Sebastien Varrette <sebastien.varrette@uni.lu>
Merge branch 'release/0.1.2' into devel

* release/0.1.2:
  bump to version '0.1.2'