Split justifyContent into separate plugin

defaultConfig.stub.js

@@ -23,6 +23,7 @@ module.exports = {
     flexWrap: ['responsive'],
     alignItems: ['responsive'],
     alignSelf: ['responsive'],
+    justifyContent: ['responsive'],
     flexbox: ['responsive'],
     float: ['responsive'],
     fontFamily: ['responsive'],

src/corePlugins.js

@@ -17,6 +17,7 @@ import flexDirection from './plugins/flexDirection'
 import flexWrap from './plugins/flexWrap'
 import alignItems from './plugins/alignItems'
 import alignSelf from './plugins/alignSelf'
+import justifyContent from './plugins/justifyContent'
 import flexbox from './plugins/flexbox'
 import float from './plugins/float'
 import fontFamily from './plugins/fontFamily'
@@ -95,6 +96,7 @@ export default function(config) {
     flexWrap,
     alignItems,
     alignSelf,
+    justifyContent,
     flexbox,
     float,
     fontFamily,

src/plugins/flexbox.js

@@ -2,21 +2,6 @@ export default function({ variants }) {
   return function({ addUtilities }) {
     addUtilities(
       {
-        '.justify-start': {
-          'justify-content': 'flex-start',
-        },
-        '.justify-end': {
-          'justify-content': 'flex-end',
-        },
-        '.justify-center': {
-          'justify-content': 'center',
-        },
-        '.justify-between': {
-          'justify-content': 'space-between',
-        },
-        '.justify-around': {
-          'justify-content': 'space-around',
-        },
         '.content-center': {
           'align-content': 'center',
         },

src/plugins/justifyContent.js

@@ -0,0 +1,24 @@
+export default function({ variants }) {
+  return function({ addUtilities }) {
+    addUtilities(
+      {
+        '.justify-start': {
+          'justify-content': 'flex-start',
+        },
+        '.justify-end': {
+          'justify-content': 'flex-end',
+        },
+        '.justify-center': {
+          'justify-content': 'center',
+        },
+        '.justify-between': {
+          'justify-content': 'space-between',
+        },
+        '.justify-around': {
+          'justify-content': 'space-around',
+        },
+      },
+      variants
+    )
+  }
+}