Cell::Time downcase format before formatting

[pacoguzman]

In the case the format is on upcase we must downcase before trying to get convert to a strftime format expression. Is the same the library is doing on DateTime cells here

[coveralls]

Coverage remained the same at 92.404% when pulling 2ccb6f5 on bebanjo:time-formatting into 62b033c on roo-rb:master.

[stevendaniels]

@pacoguzman - can you provide an example of an actual spreadsheet that uses this format?

[tgturner]

@pacoguzman I think the downcase is actually unnecessary here. I believe that we could just do something like this:

diff --git a/lib/roo/excelx/format.rb b/lib/roo/excelx/format.rb
index 1c1968a..52d70fa 100644
--- a/lib/roo/excelx/format.rb
+++ b/lib/roo/excelx/format.rb
@@ -5,8 +5,8 @@ module Roo
     module Format
       extend self
       EXCEPTIONAL_FORMATS = {
-        'h:mm am/pm' => :date,
-        'h:mm:ss am/pm' => :date
+        'h:mm AM/PM' => :date,
+        'h:mm:ss AM/PM' => :date
       }

and we could avoid it all together. Is this something you would be interested in taking on?