tests: Rename test scripts, changing - to _ for consistency.

From now on, all new tests must use underscore.

Addresses issue #727.

tests/float/math_fun_bool.py

@@ -0,0 +1,17 @@
+# Test the bool functions from math
+
+try:
+    from math import isfinite, isnan, isinf
+except ImportError:
+    print("SKIP")
+    import sys
+    sys.exit()
+
+test_values = [1, 0, -1, 1.0, 0.0, -1.0, float('NaN'), float('Inf'), 
+               -float('NaN'), -float('Inf')]
+
+functions = [isfinite, isnan, isinf]
+
+for val in test_values:
+    for f in functions:
+        print(f(val))