Remove `idb` dependency

See f3c879a3b516645f908783a92c73bdfc143f20f2 for details.

package.json

@@ -62,7 +62,6 @@
     "form-data": "^2.3.2",
     "google-libphonenumber": "^3.0.7",
     "got": "^8.2.0",
-    "idb": "https://github.com/gasi/idb.git#8efa534c41402a0685c5c716c9da38ff7435da20",
     "lodash": "^4.17.4",
     "mkdirp": "^0.5.1",
     "node-fetch": "https://github.com/scottnonnenberg/node-fetch.git#3e5f51e08c647ee5f20c43b15cf2d352d61c36b4",

yarn.lock

@@ -2724,10 +2724,6 @@ iconv-lite@0.4.19, iconv-lite@^0.4.17, iconv-lite@^0.4.19:
   version "0.4.19"
   resolved "https://registry.yarnpkg.com/iconv-lite/-/iconv-lite-0.4.19.tgz#f7468f60135f5e5dad3399c0a81be9a1603a082b"
 
-"idb@https://github.com/gasi/idb.git#8efa534c41402a0685c5c716c9da38ff7435da20":
-  version "2.1.0"
-  resolved "https://github.com/gasi/idb.git#8efa534c41402a0685c5c716c9da38ff7435da20"
-
 ieee754@^1.1.4:
   version "1.1.8"
   resolved "https://registry.yarnpkg.com/ieee754/-/ieee754-1.1.8.tgz#be33d40ac10ef1926701f6f08a2d86fbfd1ad3e4"