Merge tag '1flow-0.26.6.4' into develop

0.26.6.4 1flow-0.26.6.4
push unicorn to 17.5 (with new versioning scheme).
add the Youtube video on the landing page, given the language.
version bump for 0.26.6.5.
Merge tag '1flow-0.26.6.5' into develop

0.26.6.5 1flow-0.26.6.5
Merge branch 'release/0.26.6.5'
Fix the favicon and include the one with the right color.
version bump for 0.26.6.6.
Merge tag '1flow-0.26.6.6' into develop

0.26.6.6 1flow-0.26.6.6
Merge branch 'release/0.26.6.6'
add ecsda and pycrypto to dev-requirements, the Fabric/paramiko dependancies are not sufficient to install them in case of a crash during the bootstrap phase.
add ecdsa and pycrypto to dev-requirements, the Fabric/paramiko dependancies are not sufficient to install them in case of a crash during the bootstrap phase.
Split the `firstdata` target into 2, for the `bootstrap` not to crash on last command.
 Update the installation part in the README.md for Linux PostgreSQL specific configuration.
version bump for 0.26.6.7.
Merge branch 'release/0.26.6.7'