python3: Iso8601 print_function

Moves Iso8601 to using the print_function.
NOTE(should not use print at all here)

partial: vmware#55

pyVmomi/Iso8601.py

@@ -14,7 +14,8 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-
+from __future__ import print_function
+# TODO (hartsocks): Introduce logging to remove the need for print function.
 """
 This module is for ISO 8601 parsing
 """
@@ -253,7 +254,7 @@ def ISO8601Format(dt):
         ]:
       dt = ParseISO8601(testStr)
       if dt == None:
-         print 'Failed to parse (%s)' % testStr
+         print('Failed to parse ({0})'.format(testStr))
          assert(False)
 
       # Make sure we can translate back
@@ -262,16 +263,16 @@ def ISO8601Format(dt):
       if dt.tzinfo is None:
          dt = dt.replace(tzinfo=dt1.tzinfo)
       if dt1 != dt:
-         print 'ParseISO8601 -> ISO8601Format -> ParseISO8601 failed (%s)' % testStr
+         print('ParseISO8601 -> ISO8601Format -> ParseISO8601 failed ({0})'.format(testStr))
          assert(False)
 
       # Make sure we can parse python isoformat()
       dt2 = ParseISO8601(dt.isoformat())
       if dt2 == None:
-         print 'ParseISO8601("%s".isoformat()) failed' % testStr
+         print('ParseISO8601("{0}".isoformat()) failed'.format(testStr))
          assert(False)
 
-      print testStr, '->', dt, isoformat
+      print(testStr, '->', dt, isoformat)
 
    # Basic form
    for testStr in [
@@ -293,7 +294,7 @@ def ISO8601Format(dt):
       # Reject for now
       dt = ParseISO8601(testStr)
       if dt != None:
-         print 'ParseISO8601 (%s) should fail, but it did not' % testStr
+         print('ParseISO8601 ({0}) should fail, but it did not'.format(testStr))
          assert(False)
       #print testStr, '->', dt
       #assert(dt != None)
@@ -352,5 +353,5 @@ def ISO8601Format(dt):
         ]:
       dt = ParseISO8601(testStr)
       if dt != None:
-         print 'ParseISO8601 (%s) should fail, but it did not' % testStr
+         print('ParseISO8601 ({0}) should fail, but it did not'.format(testStr))
          assert(False)