chore: remove node 12 support (#342)

Author: ericapisani

netlify.toml

@@ -16,4 +16,4 @@ package = "."
 command = "echo onBuild"
 
 [build.environment]
-NODE_VERSION = "12.20.0"
+NODE_VERSION = "14.14.0"

package.json

@@ -65,7 +65,7 @@
     "yargs": "^17.0.0"
   },
   "engines": {
-    "node": "^12.20.0 || ^14.14.0 || >=16.0.0"
+    "node": "^14.14.0 || >=16.0.0"
   },
   "ava": {
     "verbose": true,