Fix login failure

[ChristophWurst]

Supersedes #48
Fixes #45

[Nibbels]

Nice!
When you are ready some prerelease would be a great thing. I will test the new compilation then.

Greetings

[ChristophWurst]

Works with all my keys on both FF and Chromium. Chromium apparently doesn't activate the u2f device instantly (the LED isn't blinking right away), it takes a few seconds until it's active.

[ChristophWurst]

cc @go2sh

[ChristophWurst]

You can use this zip for testing:
twofactor_u2f.tar.gz

[Nibbels]

Ok!

Seems ok.

• disabled the old app.
• deleted the apps folder
• deleted the apps database
• uploaded the new files from the zip
• activated the new app

I registered two PlugUp-Keys in Two Accounts (4 registrations)
(Different Account and same names for the USB-Keys or same USB-Keys in general did not make any collision.)

[Windows 10 64-bit]

• Chrome Version 58.0.3029.96 (64-bit): All 4 Logins worked.
  
• Firefox 53.0.2 (64-Bit): All 4 Logins worked.
• Opera 44.0.0.251024618 (PGO): All 4 Logins worked.

I did not see anything bad..!
(As stated in #45 I was never able to see the original bug, i just didnt show up on my system.)

[Nibbels]

Why is the Line 5.6 removed here when 5.6 should be allowed.
It just blinked to my eye when I read through the changes. (Note that this comment can be absolutly idiotic, because I do not know the meaning of .travis.yml at all, just a hint to have a look to this again.

)

[ChristophWurst]

5.6 is included via the matrix ;-)

It was basically run redundantly, so I removed one build.

[ChristophWurst]

Also see https://travis-ci.org/Yubico/php-u2flib-server

[Nibbels]

All the PHP changes look good or have been tested before.

[I cannot tell anything about structural things, but they do not look bad from my point of view. (Changes which are not PHP).]

[zauguin]

Looks great and works on Chromium and Firefox for me.

[ChristophWurst]

Thanks everyone for helping with this critical issue! I've packaged a nighly build https://github.com/nextcloud/twofactor_u2f/releases/tag/nightly-20170509

[coveralls]

Coverage remained the same at 59.302% when pulling d59ab69 on fix/login-failure into 936f781 on master.