Missing brackets in print function

[David Granström]

Reported from: #3

Traceback (most recent call last):
File "./tidal-bootstrap.command", line 283, in 
main()
File "./tidal-bootstrap.command", line 279, in main
check_packages()
File "./tidal-bootstrap.command", line 175, in check_packages
+ "Sorry, all packages could not be installed"
TypeError: bad operand type for unary +: 'str'