fix: upgrade big-integer from 1.6.36 to 1.6.48 (#325)

Snyk has created this PR to upgrade big-integer from 1.6.36 to 1.6.48.

See this package in npm:
https://www.npmjs.com/package/big-integer

See this project in Snyk:
https://app.snyk.io/org/kspearrin/project/38b1ffd6-0f49-4f56-b34f-c800f1e8b2aa?utm_source=github&utm_medium=upgrade-pr

package.json

@@ -76,7 +76,7 @@
     "@microsoft/signalr": "3.1.0",
     "@microsoft/signalr-protocol-msgpack": "3.1.0",
     "@nodert-win10-rs4/windows.security.credentials.ui": "^0.4.4",
-    "big-integer": "1.6.36",
+    "big-integer": "1.6.48",
     "browser-hrtime": "^1.1.8",
     "chalk": "2.4.1",
     "commander": "7.0.0",