Today's question of mine was How do I install Electrum 2.6.4 Bitcoin wallet on my Linux Mint 18.
Newer versions of Electrum are available for download. At the time of writing this, there were similar instructions to what @Vlastimil posted, but slightly altered for version 3.0, available here on the electrum.org website.
sudo apt-get install python3-pyqt5 python3-pip
sudo pip3 install https://download.electrum.org/3.0/Electrum-3.0.tar.gz
sudo apt-get install python-qt4 python-pip sudo pip install https://download.electrum.org/2.6.4/Electrum-2.6.4.tar.gz#md5=4840a883e60083d055064d5614c3353e