V3 - Remove mutable class properties plus other misc changes (#781)

* Remove the mutableValue prop in the Select component.

* Add back mutable value when Vue Select has to manage its own value.

* Remove mutableOptions, valueAsAarray. Update webpack minifer to use Terser.

* Fix tabbing

* Fix bug with showClearButton

* Fix tests.

* Call clearSelection when possible

* Update dev sandbox to have all three options for setting value.

* Update dev sandbox to display current value

* Remove unused karma test setup.

* Revert onInput name change.

* Use coveralls

* Change this.internalValue to this.$data._value.

* Remove onInput prop and replace with internal method, updateValue.

* Update tests.

* Rename optionObjectComparator to optionComparator.

build/webpack.prod.conf.js

@@ -1,3 +1,4 @@
+const TerserPlugin = require('terser-webpack-plugin');
 const merge = require('webpack-merge');
 const baseWebpackConfig = require('./webpack.base.conf');
 
@@ -9,4 +10,16 @@ module.exports = merge(baseWebpackConfig, {
     libraryTarget: 'umd',
     globalObject: 'typeof self !== \'undefined\' ? self : this',
   },
+  optimization: {
+    minimizer: [
+      new TerserPlugin({
+        sourceMap: true,
+        terserOptions: {
+          compress: {
+            drop_console: true,
+          },
+        },
+      }),
+    ],
+  }
 });