Update maxheight field to be a string

backend/right_tree/api/migrations/0011_alter_plant_maxheight.py

@@ -0,0 +1,18 @@
+# Generated by Django 3.2.8 on 2021-12-07 01:22
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('api', '0010_christchurchregion'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='plant',
+            name='maxheight',
+            field=models.CharField(max_length=20),
+        ),
+    ]