deal with empty worksheet

fix the issue:
when calling get_all_values() on empty worksheet, it will raise
exception: max() arg is an empty sequence
Update Google's application-specific password url

The old one only shows the current applications, it doesn't allow to create a new one
Merge pull request #125 from cpdomina/patch-1

Update Google's application-specific password url
Merge pull request #116 from gulige/master

deal with empty worksheet
PEP8fied
Add "If-Match" header to PUT and POST requests for new spreadsheets.

The "New" Google spreadsheets now work, once you add this header.
Before this, they could be read but not updated (though would not raise
an error). Now, read-write access is restored.

As recommended by @sadovnychyi in his comment to issue #123
https://github.com/burnash/gspread/issues/123#issuecomment-42134685
Merge pull request #127 from rwest/NewSpreadsheets

Add "If-Match" header to PUT and POST requests for new spreadsheets.
added support for new spreadsheet urls
Merge pull request #128 from pizzapanther/master

Added support for new spreadsheet urls
version bump, updated changelog
added shortcut command, courtesy of @kennethreitz
fixed regression bug #130. Not every POST needs If-Match header
bumped version
Merge pull request #1 from burnash/master

gspread update