Use a more powerfull template engine

[luisvt]

As a developer I would like to create templates that contains certain logic, for example you could add erb templates similar to yeoman and then the pubspec.yaml template could look like this:

name: <%= projectName %>
author: <%= author %>
dependencies:
<% if cssPreprocessor == 'sass' %>
  <%= sass: any %>
<% end %>
<% if cssPreprocessor == 'less' %>
  <%= less: any %>
<% end %>
<% if cssPreprocessor == 'stylus' %>
  <%= stylus: any %>
<% end %>

[kwalrath]

@devoncarew, @sethladd, @kevmoo: What do you think?

[kevmoo]

Interesting idea.

One reason we wanted something super simple: it allows us to create templates that are valid source files. This is why we use the underscore model, etc.