Remove the FAB

Fixes #58

I've tried adding a black space under the FAB, but that just reduces the
available vertical space while typing. This does reduce the usability
for small notes, as clicking on the FAB is much easier than clicking on
top-right back button or clicking the back button twice on Android.

lib/editors/checklist_editor.dart

@@ -121,7 +121,6 @@ class ChecklistEditorState extends State<ChecklistEditor>
 
     return Scaffold(
       appBar: buildEditorAppBar(widget, this),
-      floatingActionButton: buildFAB(widget, this),
       body: Column(
         children: <Widget>[
           if (widget.note.canHaveMetadata) titleEditor,

lib/editors/common.dart

@@ -85,12 +85,3 @@ AppBar buildEditorAppBar(
     ],
   );
 }
-
-FloatingActionButton buildFAB(Editor editor, EditorState editorState) {
-  return FloatingActionButton(
-    child: const Icon(Icons.check),
-    onPressed: () {
-      editor.exitEditorSelected(editorState.getNote());
-    },
-  );
-}

lib/editors/markdown_editor.dart

@@ -87,7 +87,6 @@ class MarkdownEditorState extends State<MarkdownEditor> implements EditorState {
 
     return Scaffold(
       appBar: buildEditorAppBar(widget, this, extraButtons: [extraButton]),
-      floatingActionButton: buildFAB(widget, this),
       body: body,
     );
   }

lib/editors/raw_editor.dart

@@ -70,7 +70,6 @@ class RawEditorState extends State<RawEditor> implements EditorState {
 
     return Scaffold(
       appBar: buildEditorAppBar(widget, this),
-      floatingActionButton: buildFAB(widget, this),
       body: editor,
     );
   }

lib/widgets/note_viewer.dart

@@ -60,7 +60,6 @@ class NoteViewer extends StatelessWidget {
               },
             ),
           ),
-          const SizedBox(height: 64.0),
           // _buildFooter(context),
         ],
         crossAxisAlignment: CrossAxisAlignment.start,