Samples maintenance (#435)

veggieseasons/pubspec.lock

@@ -36,13 +36,6 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.1.3"
-  clock:
-    dependency: transitive
-    description:
-      name: clock
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.0.1"
   collection:
     dependency: transitive
     description:
@@ -71,13 +64,6 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "0.1.3"
-  fake_async:
-    dependency: transitive
-    description:
-      name: fake_async
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.1.0"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -141,7 +127,7 @@ packages:
       name: path
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.7.0"
+    version: "1.6.4"
   pedantic:
     dependency: "direct dev"
     description:
@@ -155,7 +141,14 @@ packages:
       name: petitparser
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "3.0.2"
+    version: "2.4.0"
+  quiver:
+    dependency: transitive
+    description:
+      name: quiver
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.1.3"
   scoped_model:
     dependency: "direct main"
     description:
@@ -258,7 +251,7 @@ packages:
       name: xml
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "3.7.0"
+    version: "3.6.1"
   yaml:
     dependency: transitive
     description:
@@ -267,5 +260,5 @@ packages:
     source: hosted
     version: "2.2.1"
 sdks:
-  dart: ">=2.7.0 <3.0.0"
+  dart: ">=2.6.0 <3.0.0"
   flutter: ">=1.12.13+hotfix.5 <2.0.0"