build: bump bower from 1.8.2 to 1.8.4

Bumps [bower](https://github.com/bower/bower) from 1.8.2 to 1.8.4.
- [Release notes](https://github.com/bower/bower/releases)
- [Changelog](https://github.com/bower/bower/blob/master/CHANGELOG.md)
- [Commits](bower/bower@v1.8.2...v1.8.4)

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

packages/proteus/package.json

@@ -9,7 +9,7 @@
   },
   "description": "Axolotl protocol implementation for JavaScript.",
   "devDependencies": {
-    "bower": "1.8.2",
+    "bower": "1.8.4",
     "chai": "4.1.2",
     "jasmine": "3.1.0",
     "rimraf": "2.6.2",

yarn.lock

@@ -1372,9 +1372,9 @@ boom@5.x.x:
   dependencies:
     hoek "4.x.x"
 
-bower@1.8.2, bower@^1.3.12, bower@^1.4.1:
-  version "1.8.2"
-  resolved "https://registry.yarnpkg.com/bower/-/bower-1.8.2.tgz#adf53529c8d4af02ef24fb8d5341c1419d33e2f7"
+bower@1.8.4, bower@^1.3.12, bower@^1.4.1:
+  version "1.8.4"
+  resolved "https://registry.yarnpkg.com/bower/-/bower-1.8.4.tgz#e7876a076deb8137f7d06525dc5e8c66db82f28a"
 
 brace-expansion@^1.0.0, brace-expansion@^1.1.7:
   version "1.1.11"