Fix 1.2.1 to be a single choice instead of three (#43)

apps/map/migrations/0038_auto_20180328_0146.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.6 on 2018-03-28 01:46
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('map', '0037_auto_20180327_0549'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='casestudy',
+            name='sector_of_economy',
+            field=models.CharField(choices=[('RN', 'Renewable Energy Generation'), ('PG', 'Power Grids'), ('SM', 'Supply of Minerals')], help_text='Which sector of the renewable energy economy is most                    relevant?', max_length=3, verbose_name='Sector of economy'),
+        ),
+    ]