Fix tests and git migration gathering

django_migration_linter/migration.py

@@ -5,3 +5,8 @@ class Migration(object):
     def __init__(self, abs_path):
         self.abs_path = abs_path
         self.app_name, self.name = split_migration_path(self.abs_path)
+
+    def __lt__(self, other):
+        if not isinstance(other, Migration):
+            return NotImplemented
+        return self.abs_path < other.abs_path

django_migration_linter/migration_linter.py

@@ -217,7 +217,7 @@ class MigrationLinter(object):
                 re.search(r"\/{0}\/.*\.py".format(MIGRATION_FOLDER_NAME), line)
                 and "__init__" not in line
             ):
-                migrations.append(Migration(line))
+                migrations.append(Migration(os.path.join(self.django_path, line)))
         diff_process.wait()
 
         if diff_process.returncode != 0: