add file upload to planned session

rowers/models.py

@@ -2275,8 +2275,8 @@ class PlannedSession(models.Model):
 
     is_template = models.BooleanField(default=False)
 
-    fitfile = models.CharField(default=None,max_length=150,blank=True,null=True)
-    json_string = models.TextField(max_length=1000,default=None,blank=True,null=True)
+    fitfile = models.FileField(blank=True,null=True)
+    json_string = models.TextField(max_length=10000,default=None,blank=True,null=True)
     interval_string = models.TextField(max_length=1000,default=None,blank=True,null=True,
                                        verbose_name='Interval String (optional)')
 
@@ -2498,7 +2498,8 @@ class PlannedSessionForm(ModelForm):
                   'sessionunit',
                   'course',
                   'comment',
-                  'interval_string'
+                  'interval_string',
+                  'fitfile',
         ]
 
         dateTimeOptions = {