v2.1.0

• Ability to pause/resume terminal capture with C-\ key shortcut
• Desktop notifications - only for the above pause feature at the moment
• Removed dependency on tput/ncurses (thanks @arp242 / Martin Tournoij!)
• ASCIINEMA_REC env var is back (thanks @landonb / Landon Bouma!)
• Terminal answerbacks (CSI 6 n) in asciinema cat are now hidden (thanks @djpohly / Devin J. Pohly!)
• Codeset detection works on HP-UX now (thanks @michael-o / Michael Osipov!)
• Attempt at recording to existing file suggests use of --overwrite option now
• Upload for users with very long $USER is fixed
• Added official support for Python 3.8 and 3.9
• Dropped official support for EOL-ed Python 3.4 and 3.5
• Internal refactorings