add seconds option to interval_units with tests

.gitignore

@@ -66,3 +66,7 @@ target/
 
 # SQLite
 *.sqlite3
+
+# Pipenv
+Pipfile
+Pipfile.lock

scheduler/migrations/0006_auto_20181010_0102.py

@@ -0,0 +1,18 @@
+# Generated by Django 2.1.2 on 2018-10-10 01:02
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('scheduler', '0005_added_result_ttl'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='repeatablejob',
+            name='interval_unit',
+            field=models.CharField(choices=[('seconds', 'seconds'), ('minutes', 'minutes'), ('hours', 'hours'), ('days', 'days'), ('weeks', 'weeks')], default='hours', max_length=12, verbose_name='interval unit'),
+        ),
+    ]

scheduler/models.py

@@ -147,6 +147,7 @@ class Meta:
 class RepeatableJob(ScheduledTimeMixin, BaseJob):
 
     UNITS = Choices(
+        ('seconds', _('seconds')),
         ('minutes', _('minutes')),
         ('hours', _('hours')),
         ('days', _('days')),

scheduler/tests.py

@@ -233,6 +233,12 @@ def test_interval_seconds_minutes(self):
         job.interval_unit = 'minutes'
         self.assertEqual(900.0, job.interval_seconds())
 
+    def test_interval_seconds_seconds(self):
+        job = RepeatableJob()
+        job.interval = 15
+        job.interval_unit = 'seconds'
+        self.assertEqual(15.0, job.interval_seconds())
+
     def test_repeatable_schedule(self):
         job = self.JobClassFactory()
         job.id = 1