Move dev dep to the right place

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

package.json

@@ -63,7 +63,6 @@
     "matrix-js-sdk": "github:matrix-org/matrix-js-sdk#develop",
     "matrix-react-sdk": "github:matrix-org/matrix-react-sdk#develop",
     "olm": "https://packages.matrix.org/npm/olm/olm-3.1.4.tgz",
-    "postcss-easings": "^2.0.0",
     "prop-types": "^15.7.2",
     "react": "^16.9.0",
     "react-dom": "^16.9.0",
@@ -127,6 +126,7 @@
     "modernizr": "^3.6.0",
     "node-fetch": "^2.6.0",
     "optimize-css-assets-webpack-plugin": "^5.0.3",
+    "postcss-easings": "^2.0.0",
     "postcss-extend": "^1.0.5",
     "postcss-hexrgba": "^2.0.0",
     "postcss-import": "^12.0.1",