Fixed #38. Implemented the new schema.

Now we only store the date days and the commit hashes. The remote url is not used anymore. Fixes #29.
After this change, the data file is simplified a lot.

lib/index.js

@@ -14,12 +14,14 @@ var Ul = require("ul")
   , Typpy = require("typpy")
   , Exec = ChildProcess.exec
   , Spawn = ChildProcess.spawn
-  , LowDb = require("lowdb")
   ;
 
 // Constants
 const DATE_FORMAT = "MMM D, YYYY"
     , DEFAULT_STORE = Abs("~/.git-stats")
+    , DEFAULT_DATA = {
+        commits: {}
+      }
     ;
 
 function GitStats(dataPath) {
@@ -65,20 +67,18 @@ GitStats.prototype.record = function (data, callback) {
     }
 
     if (typeof data.url !== "string" || !data.url) {
-        callback(new Error("Invalid url field. This commit is not recorded into the git-stats history since you haven't added the remote url. You can import the previous commits using the git-stats-importer tool."));
-        return GitStats;
+        delete data.url;
     }
 
     // Get stats
     self.get(function (err, stats) {
-        stats = stats || {};
 
-        var day = data.date.format(DATE_FORMAT)
-          , today = stats[day] = Object(stats[day])
-          , repo = today[data.url] = Object(today[data.url])
+        var commits = stats.commits
+          , day = data.date.format(DATE_FORMAT)
+          , today = commits[day] = Object(commits[day])
           ;
 
-        repo[data.hash] = { date: data.date };
+        today[data.hash] = 1;
 
         self.save(stats, callback);
     });
@@ -100,8 +100,8 @@ GitStats.prototype.get = function (callback) {
     ReadJson(self.path, function (err, data) {
 
         if (err && err.code === "ENOENT") {
-           return self.save({}, function (err) {
-               callback(err, {});
+           return self.save(DEFAULT_DATA, function (err) {
+               callback(err, DEFAULT_DATA);
            });
         }
 
@@ -198,14 +198,11 @@ GitStats.prototype.graph = function (data, callback) {
 
         // Iterate days
         self.iterateDays(data, function (cDay) {
+            cDayObj = Object(stats.commits[cDay]);
             cDayObj = year[cDay] = {
-                _: stats[cDay] || {}
-              , c: 0
+                _: cDayObj
+              , c: Object.keys(cDayObj).length
             };
-
-            Object.keys(cDayObj._).forEach(function (c) {
-                cDayObj.c += Object.keys(cDayObj._[c]).length;
-            });
         });
 
         callback(null, year);