Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages were automatically installed and are no longer required:
  linux-headers-4.4.0-21 linux-headers-4.4.0-21-generic
  linux-image-4.4.0-21-generic linux-image-extra-4.4.0-21-generic
Use 'sudo apt autoremove' to remove them.
The following packages will be upgraded:
  emma
1 upgraded, 0 newly installed, 0 to remove and 7 not upgraded.
3 not fully installed or removed.
Need to get 66.2 kB of archives.
After this operation, 28.7 kB of additional disk space will be used.
Get:1 http://ng.archive.ubuntu.com/ubuntu xenial/universe i386 emma all 0.6-5 [66.2 kB]
Fetched 66.2 kB in 1s (49.0 kB/s)                       
debconf: unable to initialize frontend: Dialog
debconf: (Dialog frontend requires a screen at least 13 lines tall and 31 columns wide.)
debconf: falling back to frontend: Readline
(Reading database ... 365445 files and directories currently installed.)
Preparing to unpack .../archives/emma_0.6-5_all.deb ...
/var/lib/dpkg/tmp.ci/preinst: 6: /var/lib/dpkg/tmp.ci/preinst: pycentral: not found
dpkg: error processing archive /var/cache/apt/archives/emma_0.6-5_all.deb (--unpack):
 subprocess new pre-installation script returned error exit status 127
Processing triggers for menu (2.1.47ubuntu1) ...
Errors were encountered while processing:
 /var/cache/apt/archives/emma_0.6-5_all.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)