fix(manifest): update icon paths to use PNG format

Author: cmuench

icons/logo_16.png

@@ -14,21 +14,21 @@
   "action": {
     "default_popup": "popup/popup.html",
     "default_icon": {
-      "16": "icons/logo.svg",
-      "24": "icons/logo.svg",
-      "48": "icons/logo.svg",
-      "96": "icons/logo.svg"
+      "16": "icons/logo_16.png",
+      "24": "icons/logo_24.png",
+      "48": "icons/logo_48.png",
+      "96": "icons/logo_96.png"
     }
   },
   "options_ui": {
     "page": "options/options.html",
     "open_in_tab": true
   },
   "icons": {
-    "16": "icons/logo.svg",
-    "24": "icons/logo.svg",
-    "48": "icons/logo.svg",
-    "96": "icons/logo.svg"
+    "16": "icons/logo_16.png",
+    "24": "icons/logo_24.png",
+    "48": "icons/logo_48.png",
+    "96": "icons/logo_96.png"
   },
   "browser_specific_settings": {
     "gecko": {