Bump lodash from 4.17.20 to 4.17.21 in /example

Bumps [lodash](https://github.com/lodash/lodash) from 4.17.20 to 4.17.21.
- [Release notes](https://github.com/lodash/lodash/releases)
- [Commits](lodash/lodash@4.17.20...4.17.21)

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

example/package.json

@@ -9,7 +9,7 @@
   },
   "dependencies": {
     "elliptic": "^6.5.4",
-    "lodash": "^4.17.19",
+    "lodash": "^4.17.21",
     "react-app-polyfill": "^1.0.0"
   },
   "alias": {

example/yarn.lock

@@ -3089,15 +3089,10 @@ lodash.uniq@^4.5.0:
   resolved "https://registry.yarnpkg.com/lodash.uniq/-/lodash.uniq-4.5.0.tgz#d0225373aeb652adc1bc82e4945339a842754773"
   integrity sha1-0CJTc662Uq3BvILklFM5qEJ1R3M=
 
-lodash@^4.17.13, lodash@^4.17.15, lodash@^4.17.4:
-  version "4.17.15"
-  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.15.tgz#b447f6670a0455bbfeedd11392eff330ea097548"
-  integrity sha512-8xOcRHvCjnocdS5cpwXQXVzmmh5e5+saE2QGoeQmbKmRS6J3VQppPOIt0MnmE+4xlZoumy0GPG0D0MVIQbNA1A==
-
-lodash@^4.17.19:
-  version "4.17.20"
-  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.20.tgz#b44a9b6297bcb698f1c51a3545a2b3b368d59c52"
-  integrity sha512-PlhdFcillOINfeV7Ni6oF1TAEayyZBoZ8bcshTHqOYJYlrqzRK5hagpagky5o4HfCzzd1TRkXPMFq6cKk9rGmA==
+lodash@^4.17.13, lodash@^4.17.15, lodash@^4.17.21, lodash@^4.17.4:
+  version "4.17.21"
+  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.21.tgz#679591c564c3bffaae8454cf0b3df370c3d6911c"
+  integrity sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg==
 
 log-symbols@^2.2.0:
   version "2.2.0"