remove old rails syntax
Merge pull request #52 from railsgirls-jp/remove-old-syntax

remove old rails syntax
Adds clearer places where people should try the added stuff
Updates RailsInstaller links to new version
Expanded info on promotion and coaches
Merge pull request #53 from ialja/master

Expanded info on promotion and coaches
Fixes small typo
Added a new guide for coaches
Added a bit more info about the required number of coaches
Merge pull request #54 from ialja/master

Prepared a guide for coaches
Added Aljas Guide :)
Fix a broken link in the guide

One link is missing the `http://` scheme and thus does not work.
Merge pull request #55 from mitio/patch-1

Fix a broken link in the guide
Fix a typo in #### What is expected from the coaches?
Fix wording for Step 1

Step 1 wording is too verbose considering we have already instructed the
student to run acommand in the terminal in Step 0 without all this
explanation.
Remove wrong instruction from Step 2

This guide is a continuation of the Rails Girls App Tutorial where the
student has already added a root route.
Simplify Step 3

Make Step 3 simpler and straightforward with clear instructions to
follow and a note for the coach to explian what the default user model
is
Simplify instructions for Step 4

Stuends can use the sign up form to create an account and don't need to
use the console. Also, the console example was wrong, since the default
pasword length must be at least 8 chars long and the example showed a
7-chars password.
Simplify Step 5

Clean erb examples, fix highlight to erb and add coach notes.
Credit for the updates