[BUGIFX] ensure git is installed

[andreaswolf]

I would rather like to not tie this directly to one family of OSes. Then let’s see if we can instead download the zip file from Github instead (which would also make the process a lot faster).

[emmetog]

How about using a conditional, like this:

- name: ensure git is present (apt)
  apt: name=git state=present cache_valid_time=3600 update_cache=yes
  when: ansible_pkg_mgr == 'apt'

- name: ensure git is present (yum)
  yum: name=git state=present update_cache=yes
  when: ansible_pkg_mgr == 'yum'