A new feature for switching environment of data table. 

We used cucumber to test our websites and met a problem about the data table of scenario outline features. 
Data table will test all data rows which we defined, but we need to skip some data rows when these testing are running in different environment, such as alpha, beta, production.


Here is the example of new feature.
<pre>
     Feature: testing scenarios
        Scenario Outline: scenario outline 1
          When step <id>

        Examples:
          |_env   | id |
          | alpha | a  |
          | beta  | b  |
          | all   | c  |
</pre>
If you executed command cucumber.js append with "-data_env beta", then cucumber will only execute two data rows, both of them are "beta" and "all". 
<pre>
jasmine-node spec && ./bin/cucumber.js -i features/xx.feature  -data_env beta
</pre>