Make more gen-* scripts py3 compatible (#940)

diff --git a/src/gen-unicode-ranges.py b/src/gen-unicode-ranges.py
index 3b59cd8..30249a8 100644
--- a/src/gen-unicode-ranges.py
+++ b/src/gen-unicode-ranges.py
@@ -4,6 +4,8 @@
 # Input is a tab seperated list of unicode ranges from the otspec
 # (https://docs.microsoft.com/en-us/typography/opentype/spec/os2#ulunicoderange1).
 
+from __future__ import print_function, division, absolute_import
+
 import io
 import re
 import sys
@@ -11,7 +13,7 @@
 reload(sys)
 sys.setdefaultencoding('utf-8')
 
-print (u"""static Range os2UnicodeRangesSorted[] =
+print ("""static Range os2UnicodeRangesSorted[] =
 {""")
 
 args = sys.argv[1:]
@@ -47,6 +49,6 @@
   end = ("0x%X" % ranges[1]).rjust(8)
   bit = ("%s" % ranges[2]).rjust(3)
 
-  print "  {%s, %s, %s}, // %s" % (start, end, bit, ranges[3])
+  print ("  {%s, %s, %s}, // %s" % (start, end, bit, ranges[3]))
 
-print (u"""};""");
+print ("""};""")