Sometimes passwords, URLs and other values of the variables can
contain special symbols, for example the dollar sign, using these
values can lead to unpredictable attempts of the variable expansions
in the Bash scripts, such as openrc file, so we need to use single
quotes for all variables values.

Change-Id: Ib2aabadd0ffd6a8dc2591245f29b4478e03d92fc
Signed-off-by: Maksim Malchuk <maksim.malchuk@gmail.com>