chore: upgrade dependencies to latest versions (#19)

.github/workflows/master.yml

@@ -19,8 +19,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: subosito/flutter-action@v1
         with:
-          channel: dev
-          flutter-version: "2.6.0-11.0.pre"
+          channel: stable
 
       - name: Install dependencies
         run: flutter pub get
@@ -48,8 +47,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: subosito/flutter-action@v1
         with:
-          channel: dev
-          flutter-version: "2.6.0-11.0.pre"
+          channel: stable
 
       - name: Install dependencies
         run: flutter pub get

pubspec.yaml

@@ -3,8 +3,8 @@ description: Dart bindings to libgit2
 version: 0.0.1
 
 environment:
-  sdk: ">=2.15.0-82.0.dev <3.0.0"
-  flutter: ">=2.5.0"
+  sdk: ">=2.15.0 <3.0.0"
+  flutter: ">=2.8.0"
 
 dependencies:
   args: ^2.3.0
@@ -13,10 +13,10 @@ dependencies:
   pub_cache: ^0.3.1
 
 dev_dependencies:
-  ffigen: ^4.0.0
+  ffigen: ^4.1.2
   lints: ^1.0.1
-  path: ^1.8.0
-  test: ^1.17.5
+  path: ^1.8.1
+  test: ^1.20.0
 
 flutter:
   plugin: