fix: allow merging ``float`` values also.

bin/compose-core

@@ -216,7 +216,7 @@ def merge(*args):
         return None
     if len(args) == 1:
         return args[0]
-    if all(isinstance(arg, (int, basestring, bool)) for arg in args):
+    if all(isinstance(arg, (int, basestring, bool, float)) for arg in args):
         return args[-1]
     elif all(isinstance(arg, list) for arg in args):
         res = []