Consistent use of strings in provision.sh

Use echo in favor of printf to not have to add \n each time; use quotation marks around strings consistently; minor string changes
Use `-e` flag to enable interpretation of backslash escapes

We do use `\n` from time to time for additional spacing around lines. `echo` does not handle this by default until a flag is used to do so.

Work towards #133
Small formatting change in terminal output

Work toward #133
Updated contributors list