Recently I faced some dependency issues trying to install Ansible 2 on Debian 8 (Jessie). Googling a bit I found a solution which was a basically to upgrade or install missing dependencies. Following script automates the installation procedure:

sudo apt-get update
sudo apt-get install build-essential libssl-dev libffi-dev python-dev python-pip python-dev git -y
sudo pip install PyYAML jinja2 paramiko
sudo pip install pyasn1 --upgrade
sudo pip install c

git clone
cd ansible

## This is important since core and extra modules are in separate repositories!
git submodule update --init --recursive

## I want to get a stable release, so I checkout a specific tag
git tag -l
git checkout tags/v2.1.1.0-1

## Build Ansible from sources
sudo make install

## If Build fails, then cleanup before retry
sudo make clean

sudo mkdir /etc/ansible
sudo cp ~/ansible/examples/hosts /etc/ansible/