script: use double quotes for strings

unless there is a double quote in the string

Signed-off-by: Corey Powell <mistdragon100@gmail.com>
script: refactored slugrunner/runner/init

Signed-off-by: Corey Powell <mistdragon100@gmail.com>
script: refactored slugbuiler shell scripts

Signed-off-by: Corey Powell <mistdragon100@gmail.com>