Remove plausible experiment

Not being used, and it's easier to just run our own db. Plausible is not
built for app analytics.

lib/analytics/plausible.dart

@@ -1,66 +0,0 @@
-import 'dart:convert';
-
-// import 'package:http/http.dart' as http;
-
-class PlausibleEvent {
-  String eventName = "";
-  String href = "";
-  String hostname = "";
-
-  String referrer = "";
-  int innerWidth = 0;
-  bool hash = false;
-  Map<String, dynamic> props = {};
-
-  static final _acceptedPayloadTypes = [int, double, String, bool];
-  Map<String, dynamic> toMap() {
-    assert(() {
-      for (var entry in props.entries) {
-        var type = entry.value.runtimeType;
-        if (!_acceptedPayloadTypes.contains(type)) {
-          return false;
-        }
-      }
-      return true;
-    }(), "Plausible Event Payload contains unsupported type");
-
-    return {
-      'n': eventName,
-      'u': href,
-      'd': hostname,
-      'r': referrer,
-      'w': innerWidth,
-      'h': hash ? 1 : 0,
-      'p': json.encode(props),
-    };
-  }
-
-  String toJson() => json.encode(toMap());
-}
-
-/*
-
-void main() async {
-  const apiHost = 'plausible.gitjournal.io';
-  var event = PlausibleEvent();
-  event.eventName = 'gitjournal_test';
-  event.hostname = 'gitjournal.io';
-  event.href = 'https://gitjournal.io/mobile_analytics';
-
-  var post = http.post(
-    Uri.https(apiHost, '/api/event'),
-    // FIXME: Why is this not application/json ?
-    // Taken from - https://github.com/plausible/tracker/blob/master/src/index.js
-    headers: <String, String>{
-      'Content-Type': 'text/plain',
-    },
-    body: event.toJson(),
-  );
-  var response = await post;
-  print('Posted');
-  print('Status Code: ${response.statusCode}');
-  print('Headers: ${response.headers}');
-  print('Body: ${response.bodyBytes.toString()}');
-}
-
-*/

test/analytics/plausible.dart

@@ -1,31 +0,0 @@
-import 'package:test/test.dart';
-
-import 'package:gitjournal/analytics/plausible.dart';
-
-final Matcher throwsAssertionError = throwsA(isA<AssertionError>());
-
-void main() {
-  test('Serialization', () {
-    var e = PlausibleEvent();
-    e.props = {
-      'a': 1,
-      'b': 5.5,
-      'c': false,
-      'd': 'Hello',
-    };
-
-    expect(e.toJson(), isNotEmpty);
-  });
-
-  test('Invalid Serialization', () {
-    var fn = () {
-      var e = PlausibleEvent();
-      e.props = {
-        'a': [1],
-      };
-      e.toJson();
-    };
-
-    expect(fn, throwsAssertionError);
-  });
-}