Explicitly exclude pre-Chromium Edge from CDN builds

The >1% was sometimes including this and other times not depending on CI vs. local, couldn't quite figure out why, guessing some difference in version of caniuse-lite.

__tests__/cli.test.js

@@ -87,13 +87,13 @@ describe('cli', () => {
 
     it('compiles CSS file with autoprefixer', () => {
       return cli(['build', inputCssPath]).then(() => {
-        expect(process.stdout.write.mock.calls[0][0]).toContain('-ms-input-placeholder')
+        expect(process.stdout.write.mock.calls[0][0]).toContain('-webkit-max-content')
       })
     })
 
     it('compiles CSS file without autoprefixer', () => {
       return cli(['build', inputCssPath, '--no-autoprefixer']).then(() => {
-        expect(process.stdout.write.mock.calls[0][0]).not.toContain('-ms-input-placeholder')
+        expect(process.stdout.write.mock.calls[0][0]).not.toContain('-webkit-max-content')
       })
     })
   })

package.json

@@ -74,6 +74,7 @@
   },
   "browserslist": [
     "> 1%",
+    "not edge <= 18",
     "not ie 11",
     "not op_mini all"
   ],