Extract correct instrument name from spectrum filename [fixes #146]

Author: tboggs

spectral/database/ecostress.py

@@ -194,7 +194,7 @@ class Sig:
                                   s['particle size'], sampleNum, s['owner'],
                                   s['origin'], phase, s['description'])
 
-            instrument = os.path.basename(f).split('.')[1]
+            instrument = os.path.basename(f).split('.')[-3]
             environment = 'lab'
             m = sig.measurement