Add display flex

Only added display because I don't know which flex properties
need snippets.  I'm open to suggestions.

Fixes dsandstrom#14

Author: dsandstrom

snippets/css-snippets.cson

@@ -101,6 +101,9 @@
   'display: none':
     'prefix': 'disn'
     'body': 'display: none$0'
+  'display: flex':
+    'prefix': 'disf'
+    'body': 'display: flex$0'
   'fill':
     'prefix': 'fill'
     'body': 'fill: ${1:#${2:000000}}$0'
@@ -436,6 +439,9 @@
   'display: none':
     'prefix': 'disn'
     'body': 'display: none;$0'
+  'display: flex':
+    'prefix': 'disf'
+    'body': 'display: flex;$0'
   'fill':
     'prefix': 'fill'
     'body': 'fill: ${1:#${2:000000}};$0'