diff --git a/pubspec.lock b/pubspec.lock
index 3562e612a..10e5d7d0b 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -42,7 +42,7 @@ packages:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.4.2"
+    version: "2.4.1"
   barcode:
     dependency: transitive
     description:
@@ -64,13 +64,6 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "2.2.0+1"
-  characters:
-    dependency: transitive
-    description:
-      name: characters
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.0.0"
   charcode:
     dependency: transitive
     description:
@@ -112,7 +105,7 @@ packages:
       name: collection
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.14.13"
+    version: "1.14.12"
   console_log_handler:
     dependency: transitive
     description:
@@ -133,14 +126,14 @@ packages:
       name: coverage
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.14.0"
+    version: "0.13.11"
   crypto:
     dependency: transitive
     description:
       name: crypto
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.5"
+    version: "2.1.4"
   csslib:
     dependency: transitive
     description:
@@ -173,20 +166,13 @@ packages:
       url: "git://github.com/deckerst/expansion_tile_card.git"
     source: git
     version: "1.0.3"
-  fake_async:
-    dependency: transitive
-    description:
-      name: fake_async
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.1.0"
   file:
     dependency: transitive
     description:
       name: file
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "5.2.1"
+    version: "5.1.0"
   firebase_crashlytics:
     dependency: "direct main"
     description:
@@ -275,7 +261,7 @@ packages:
       name: flutter_svg
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.18.0"
+    version: "0.17.4"
   flutter_test:
     dependency: "direct dev"
     description: flutter
@@ -353,7 +339,7 @@ packages:
       name: image
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.14"
+    version: "2.1.12"
   intl:
     dependency: "direct main"
     description:
@@ -381,7 +367,7 @@ packages:
       name: json_rpc_2
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.2.1"
+    version: "2.1.0"
   latlong:
     dependency: "direct main"
     description:
@@ -416,7 +402,7 @@ packages:
       name: matcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.12.8"
+    version: "0.12.6"
   meta:
     dependency: transitive
     description:
@@ -438,6 +424,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "0.9.7"
+  multi_server_socket:
+    dependency: transitive
+    description:
+      name: multi_server_socket
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.0.2"
   nested:
     dependency: transitive
     description:
@@ -500,7 +493,7 @@ packages:
       name: path
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.7.0"
+    version: "1.6.4"
   path_drawing:
     dependency: transitive
     description:
@@ -584,7 +577,7 @@ packages:
       name: petitparser
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "3.0.4"
+    version: "2.4.0"
   photo_view:
     dependency: "direct main"
     description:
@@ -642,7 +635,7 @@ packages:
       name: process
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "3.0.13"
+    version: "3.0.12"
   proj4dart:
     dependency: transitive
     description:
@@ -801,7 +794,7 @@ packages:
       name: stack_trace
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.9.5"
+    version: "1.9.3"
   stream_channel:
     dependency: transitive
     description:
@@ -857,21 +850,21 @@ packages:
       name: test
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.15.2"
+    version: "1.14.4"
   test_api:
     dependency: transitive
     description:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.17"
+    version: "0.2.15"
   test_core:
     dependency: transitive
     description:
       name: test_core
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.3.10"
+    version: "0.3.4"
   transparent_image:
     dependency: transitive
     description:
@@ -892,7 +885,7 @@ packages:
       name: typed_data
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0"
+    version: "1.1.6"
   unicode:
     dependency: transitive
     description:
@@ -1025,7 +1018,7 @@ packages:
       name: xml
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "4.2.0"
+    version: "3.6.1"
   yaml:
     dependency: transitive
     description:
@@ -1034,5 +1027,5 @@ packages:
     source: hosted
     version: "2.2.1"
 sdks:
-  dart: ">=2.9.0-14.0.dev <3.0.0"
-  flutter: ">=1.18.0-6.0.pre <2.0.0"
+  dart: ">=2.8.0 <3.0.0"
+  flutter: ">=1.17.0 <2.0.0"