Merge branch 'release/0.2.9' into devel

* release/0.2.9:
  Update Gemfile.lock accordingly
  bump to version '0.2.9'
publish tags upon release

Signed-off-by: Sebastien Varrette <sebastien.varrette@uni.lu>
update Chaneglog

Signed-off-by: Sebastien Varrette <sebastien.varrette@uni.lu>
correct gittip

Signed-off-by: Sebastien Varrette <sebastien.varrette@uni.lu>
new gittip badge

Signed-off-by: Sebastien Varrette <sebastien.varrette@uni.lu>
restore gittip

Signed-off-by: Sebastien Varrette <sebastien.varrette@uni.lu>
restore gittip

Signed-off-by: Sebastien Varrette <sebastien.varrette@uni.lu>
complete GitFlow.init with warning messages

Signed-off-by: Sebastien Varrette <sebastien.varrette@uni.lu>
complete Git.subtree_init?

Signed-off-by: Sebastien Varrette <sebastien.varrette@uni.lu>
document subtree/submodules

Signed-off-by: Sebastien Varrette <sebastien.varrette@uni.lu>
upgrade some task desc

Signed-off-by: Sebastien Varrette <sebastien.varrette@uni.lu>
add bootstrap script

Signed-off-by: Sebastien Varrette <sebastien.varrette@uni.lu>
complete setup task

Signed-off-by: Sebastien Varrette <sebastien.varrette@uni.lu>
better Rakefile

Signed-off-by: Sebastien Varrette <sebastien.varrette@uni.lu>
correction

Signed-off-by: Sebastien Varrette <sebastien.varrette@uni.lu>
better bootstrap script

Signed-off-by: Sebastien Varrette <sebastien.varrette@uni.lu>
upgrade README

Signed-off-by: Sebastien Varrette <sebastien.varrette@uni.lu>
bump to version '0.2.10'

Signed-off-by: Sebastien Varrette <sebastien.varrette@uni.lu>
Update Gemfile.lock accordingly

Signed-off-by: Sebastien Varrette <sebastien.varrette@uni.lu>
update Changelog

Signed-off-by: Sebastien Varrette <sebastien.varrette@uni.lu>