replace nose assertions with simple asserts

test/bdd/steps/check_functions.py

@@ -0,0 +1,12 @@
+"""
+Collection of assertion functions used for the steps.
+"""
+
+class Almost:
+
+    def __init__(self, value, offset=0.00001):
+        self.value = value
+        self.offset = offset
+
+    def __eq__(self, other):
+        return abs(other - self.value) < self.offset