Update install instructions

[sirex]

Replace all sudo commands with make ubuntu and replace PostgreSQL user creation with on command (as in comments if you are not sure how to do that).

[edvinasv]

I suppose "virtualenv" has to be installed as well:

edvinas@ubuntu-VirtualBox:/git/website$ make
virtualenv --no-site-packages --python=python3 .
make: virtualenv: Command not found
Makefile:32: recipe for target 'bin/pip' failed
make: *** [bin/pip] Error 127
edvinas@ubuntu-VirtualBox:/git/website$

Therefore virtualenv was added to "make ubuntu".

[edvinasv]

"make run" is updated to listen on all IP's in case development environment is not a localhost.

[edvinasv]

edvinas@ubuntu-VirtualBox:~/git/website$ git remote show origin

• remote origin
  Fetch URL: git@github.com:python-dirbtuves/website.git
  Push URL: git@github.com:python-dirbtuves/website.git
  HEAD branch: master
  Remote branches:
  Attendance tracked
  about-page tracked
  comments tracked
  comments-reply tracked
  event-details tracked
  event-map-fix tracked
  install_instructions tracked

[edvinasv]

edvinas@ubuntu-VirtualBox:~/git/website$ git log -p -1