let 'SPECTRA' instrument_types through (don't filter)

1M0-NRES-SCICAM instruments are not of type IMAGE and were
being filtered from the returned instrument list. This was
preventing radial velocity and flux standards from being
submitted. (Issue with FLOYDS as well).

tom_observations/facilities/lco.py

@@ -406,11 +406,17 @@ def layout(self):
         )
 
     def get_instruments(self):
+        """Filter the instruments from the OCSBaseObservationForm.get_instruments()
+        (i.e. the super class) in an LCO-specifc way.
+        """
         instruments = super().get_instruments()
-        return {
+        filtered_instruments = {
             code: instrument for (code, instrument) in instruments.items() if (
-                'IMAGE' == instrument['type'] and 'MUSCAT' not in code and 'SOAR' not in code)
+                instrument['type'] in ['IMAGE', 'SPECTRA'] and (
+                'MUSCAT' not in code and
+                'SOAR' not in code))
         }
+        return filtered_instruments
 
     def all_optical_element_choices(self, use_code_only=False):
         return sorted(set([
@@ -433,8 +439,8 @@ def _build_instrument_configs(self):
                 'filter': self.cleaned_data['filter']
             }
         }
-
-        return [instrument_config]
+        instrument_configs = [instrument_config]
+        return instrument_configs
 
 
 class LCOFullObservationForm(OCSFullObservationForm):