Load / save login settings

- Using simple shared_preferences package for now

pubspec.yaml

@@ -1,5 +1,5 @@
-name: inventree_app
-description: InvenTree mobile application
+name: InvenTree
+description: InvenTree stock management
 
 # The following defines the version and build number for your application.
 # A version number is three numbers separated by dots, like 1.2.43
@@ -24,6 +24,7 @@ dependencies:
   # Use with the CupertinoIcons class for iOS style icons.
   cupertino_icons: ^0.1.2
   http: ^0.12.0+2
+  shared_preferences: ^0.5.3+1
 
 dev_dependencies:
   flutter_test: