Improve small details in specs:

* Fix coding standards;
* Simplify some expectations (eq instead of be matcher);
* Expect identity on block instead of calling;
* Change some before call as oneliners;
* Avoid shadowing variable names;
* Improve wording where needed.

spec/producer/core/task_spec.rb

@@ -3,24 +3,24 @@ require 'spec_helper'
 module Producer::Core
   describe Task do
     let(:name)      { :some_task }
-    let(:action)    { double('action') }
-    let(:condition) { double('condition') }
+    let(:action)    { double 'action' }
+    let(:condition) { double 'condition' }
     subject(:task)  { Task.new(name, [action], condition) }
 
     describe '.evaluate' do
-      let(:env)   { double('env') }
-      let(:block) { proc { :some_value } }
+      let(:env)   { double 'env' }
+      let(:block) { proc { :some_task_code } }
 
       it 'delegates to DSL.evaluate' do
         expect(Task::DSL)
           .to receive(:evaluate).with(name, env) do |&b|
-            expect(b.call).to eq :some_value
+            expect(b).to be block
           end
         Task.evaluate(name, env, &block)
       end
 
       it 'returns the evaluated task' do
-        task = double('task')
+        task = double 'task'
         allow(Task::DSL).to receive(:evaluate) { task }
         expect(Task.evaluate(name, env, &block)).to be task
       end
@@ -40,7 +40,7 @@ module Producer::Core
       end
 
       context 'when only the name is given as argument' do
-        subject(:task)  { Task.new(name) }
+        subject(:task) { Task.new(name) }
 
         it 'assigns no action' do
           expect(task.actions).to be_empty