Add PurgeCSS

yarn.lock

@@ -763,6 +763,14 @@
     exec-sh "^0.3.2"
     minimist "^1.2.0"
 
+"@fullhuman/postcss-purgecss@^1.2.0":
+  version "1.2.0"
+  resolved "https://registry.yarnpkg.com/@fullhuman/postcss-purgecss/-/postcss-purgecss-1.2.0.tgz#a3207a0e1812f8b56fa49fba5796a1020f2756a8"
+  integrity sha512-An05jbnZVUrX+VVNniaNQtOuo/S7tyQu5x86itXTF+7kfMaGxglFGykFX2KCt2hcbJijbvfCval9IkPO19V1KA==
+  dependencies:
+    postcss "^7.0.14"
+    purgecss "^1.3.0"
+
 "@hapi/address@2.x.x":
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/@hapi/address/-/address-2.0.0.tgz#9f05469c88cb2fd3dcd624776b54ee95c312126a"
@@ -8719,6 +8727,16 @@ punycode@^2.1.0, punycode@^2.1.1:
   resolved "https://registry.yarnpkg.com/punycode/-/punycode-2.1.1.tgz#b58b010ac40c22c5657616c8d2c2c02c7bf479ec"
   integrity sha512-XRsRjdf+j5ml+y/6GKHPZbrF/8p2Yga0JPtdqTIY2Xe5ohJPD9saDJJLPvp9+NSBprVvevdXZybnj2cv8OEd0A==
 
+purgecss@^1.3.0:
+  version "1.3.0"
+  resolved "https://registry.yarnpkg.com/purgecss/-/purgecss-1.3.0.tgz#fc3c303df9a74a75547545b2c0da28a9ec63da00"
+  integrity sha512-0UMnr8aUsPO7RbzAT72UELRvwMHhadtuunDm7rcgRS6b8pCVO8yglIqikiYFwQk2XP606mk+GpjI1G74Auxgtg==
+  dependencies:
+    glob "^7.1.3"
+    postcss "^7.0.14"
+    postcss-selector-parser "^6.0.0"
+    yargs "^13.2.2"
+
 q@^1.1.2:
   version "1.5.1"
   resolved "https://registry.yarnpkg.com/q/-/q-1.5.1.tgz#7e32f75b41381291d04611f1bf14109ac00651d7"
@@ -11032,7 +11050,7 @@ yargs@^11.0.0:
     y18n "^3.2.1"
     yargs-parser "^9.0.2"
 
-yargs@^13.0.0:
+yargs@^13.0.0, yargs@^13.2.2:
   version "13.3.0"
   resolved "https://registry.yarnpkg.com/yargs/-/yargs-13.3.0.tgz#4c657a55e07e5f2cf947f8a366567c04a0dedc83"
   integrity sha512-2eehun/8ALW8TLoIl7MVaRUrg+yCnenu8B4kBlRxj3GJGDKU1Og7sMXPNm1BYyM1DOJmTZ4YeN/Nwxv+8XJsUA==