add page for assigning mechanic to job
improve naming, architecture and code style in pick mechanic feature

move mechanic choosing logic to appointment controller
remove bug fixing task name(mechanic/job/_job.html.haml) into separete commit on master
rename before filter which find job for appointmenting
add method into jobs model which assign mechanic by params
rename in jobs table field date to sheduled_at
add assigned_at field for jobs
Merge pull request #38 from laudeego/em-pick-mechanic-page-list-all

add page for assigning mechanic to job