tests/float: Make various tests skippable.

tests/float/array_construct.py

 # test construction of array from array with float type
 
+try:
     from array import array
+except ImportError:
+    import sys
+    print("SKIP")
+    sys.exit()
 
 print(array('f', array('h', [1, 2])))
 print(array('d', array('f', [1, 2])))

tests/float/builtin_float_minmax.py

 # test builtin min and max functions with float args
+try:
+    min
+    max
+except:
+    import sys
+    print("SKIP")
+    sys.exit()
 
 print(min(0,1.0))
 print(min(1.0,0))

tests/float/float_array.py

+try:
     from array import array
+except ImportError:
+    import sys
+    print("SKIP")
+    sys.exit()
 
 def test(a):
     print(a)

tests/float/float_struct.py

 # test struct package with floats
-
+try:
     try:
         import ustruct as struct
     except:
         import struct
+except ImportError:
+    import sys
+    print("SKIP")
+    sys.exit()
 
 i = 1. + 1/2
 # TODO: it looks like '=' format modifier is not yet supported