Dev setup fixes

Improving instructions are database setup for apidoc.  Using backticks instead.

of system so the dev script so output will hit the console (instead of failing
silently).
Would prefer to avoid changing dev.rb - it's generated by sem directly so if we change it we should change it there:

https://github.com/gilt/schema-evolution-manager/blob/master/template/dev.rb

and maybe use "==>" rather than the word "executing"