Support Debian for `./mach bootstrap`

The Travis builders are detected as Debian for some reason by bootstrap.
servo · aneeshusa · Apr 12, 2017 · Apr 12, 2017 · Apr 12, 2017 · May 6, 2017
commit b87e0562e6d6d384945a915f63132b220bd54b6c
diff --git a/python/init.sls b/python/init.sls
@@ -18,7 +18,7 @@ python3:
       {% endif %}
       {% endif %}
 
-{% if grains['os'] == 'Ubuntu' %}
+{% if grains['os_family'] == 'Debian' %}
 python2-dev:
   pkg.installed:
     - pkgs:
@@ -28,7 +28,7 @@ python2-dev:
 pip:
   pkg.installed:
     - pkgs:
-      {% if grains['os'] in ['CentOS', 'Fedora', 'Ubuntu'] %}
+      {% if grains['os'] in ['CentOS', 'Fedora', 'Ubuntu', 'Debian'] %}
       - python-pip
       {% elif grains['os'] == 'MacOS' %}
       - python # pip is included with python in homebrew

diff --git a/servo-build-dependencies/init.sls b/servo-build-dependencies/init.sls
@@ -16,7 +16,7 @@ servo-dependencies:
       - openssl
       - pkg-config
       - yasm
-      {% elif grains['os'] == 'Ubuntu' %}
+      {% elif grains['os_family'] == 'Debian' %}
       - autoconf2.13
       - curl
       - freeglut3-dev