a more accurate way to make sure git 2.11 is installed

Change-Id: I9088295f149d65b4efcf74e991b778020b624955
diff --git a/ansible/roles/buildtools/defaults/main.yml b/ansible/roles/buildtools/defaults/main.yml
index 201b49c..b4776bb 100644
--- a/ansible/roles/buildtools/defaults/main.yml
+++ b/ansible/roles/buildtools/defaults/main.yml
@@ -1,3 +1,3 @@
 apt_packages:
   - maven
-  - git
+  - git=1:2.11*
diff --git a/ansible/roles/buildtools/tasks/main.yml b/ansible/roles/buildtools/tasks/main.yml
index 1cca698..87bd6c0 100644
--- a/ansible/roles/buildtools/tasks/main.yml
+++ b/ansible/roles/buildtools/tasks/main.yml
@@ -4,10 +4,6 @@
     state: present
     update_cache: yes
 
-- name: Upgrade Packages
-  apt:
-    upgrade: yes
-
 - name: Apt packages
   apt:
     name: "{{ item }}"