Bump axios from 0.18.1 to 0.21.1

Bumps [axios](https://github.com/axios/axios) from 0.18.1 to 0.21.1.
- [Release notes](https://github.com/axios/axios/releases)
- [Changelog](https://github.com/axios/axios/blob/v0.21.1/CHANGELOG.md)
- [Commits](axios/axios@v0.18.1...v0.21.1)

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

Author: dependabot[bot]

npm-shrinkwrap.json

@@ -11,7 +11,7 @@
   },
   "dependencies": {
     "@etclabscore/ethereum-json-rpc": "^1.3.6",
-    "axios": "^0.18.1",
+    "axios": "^0.21.1",
     "bip39": "^2.5.0",
     "bitcoinjs-lib": "^4.0.2",
     "coinselect": "^3.1.11",