Ubuntu 16.10 Dual Boot error - 'grub-efi-amd64-signed' package failed to install

I suspect that the problem is related to the fact that your computer is using an NVMe "disk" device. Such devices are still new enough that they cause problems for many tools. My hypothesis is that the Ubuntu installer, or a tool on which it relies, is becoming confused by the NVMe device and so is failing to install correctly. The Boot Info Script that you ran seems to be a bit confused, too, so I'm working on incomplete information -- but I do have enough to suggest a workaround:

1. If you haven't already done so, disable Secure Boot.
2. Download the USB flash drive of my rEFInd boot manager. (There are download links for a USB image on that page.)
3. Prepare a USB flash drive with rEFInd.
4. Boot the USB flash drive with rEFInd. You should see the rEFInd menu, and it should show options to boot both Ubuntu and Windows.
5. Select the Ubuntu boot option in rEFInd. With any luck, Ubuntu will boot up.
6. If Ubuntu boots, download the latest test/development version of rEFInd using this link. That's a Debian package that you can install by typing sudo dpkg -i refind_0.10.4.2-0ppa1_amd64.deb from the directory in which it resides. Note that I'm specifying you use this version because it includes some fixes for NVMe-related issues in the installer. The older official release version (0.10.4) might work, but this one's fixes might be required for you. Anybody reading this much past February 22, 2017 should check the main rEFInd page (above) to see if a newer version is available and, if one is, use it instead.
7. Reboot and hope for the best.

With any luck, your system will boot up to rEFInd, which should enable you to boot either Windows or Ubuntu. Note, however, that I can't promise this procedure will work; there are any number of points where it might fail. If you run into problems, please feel free to post back with more details.

Instead of installing rEFInd in step #6, you could try installing GRUB manually by typing sudo grub-install; however, whatever problem blocked the GRUB installation in the installer is likely to block this procedure, too, which is why I recommended installing rEFInd above. You could try this, though, if you prefer to use GRUB. If nothing else, installing GRUB from the console in this way is likely to produce better error messages than what the Ubuntu installer produced.