#238 Fix

* adds casting from Decimal() to primitive float for proper calculation

api/tests/v1/create/deduction_create_post_body.json

@@ -1,5 +1,5 @@
 {
     "eco_account": "CHANGE_BEFORE_RUN!!!",
-    "surface": 500.0,
+    "surface": 500.50,
     "intervention": "CHANGE_BEFORE_RUN!!!"
 }

api/tests/v1/update/deduction_update_put_body.json

@@ -1,5 +1,5 @@
 {
     "eco_account": "CHANGE_BEFORE_RUN!!!",
-    "surface": 523400.0,
+    "surface": 523400.50,
     "intervention": "CHANGE_BEFORE_RUN!!!"
 }