contribution guideline to branch off development

Author: vikasnautiyal

CONTRIBUTING.md

@@ -130,8 +130,6 @@ rake
 
 Generally, we follow the style guidelines as suggested by the official language. However, we ask that you conform to the styles that already exist in the library. If you wish to deviate, please explain your reasoning.
 
-Generally, we follow the style guidelines as suggested by the official language. However, we ask that you conform to the styles that already exist in the library. If you wish to deviate, please explain your reasoning.
-
 - [Community Driven Style Guide](https://github.com/bbatsov/ruby-style-guide)
 
 Please run your code through:
@@ -159,7 +157,7 @@ Please run your code through:
    git pull upstream <dev-branch>
    ```
 
-3. Create a new topic branch (off the main project development branch) to
+3. Create a new topic branch off the `development` branch to
    contain your feature, change, or fix:
 
    ```bash
@@ -179,7 +177,7 @@ Please run your code through:
 5. Locally merge (or rebase) the upstream development branch into your topic branch:
 
    ```bash
-   git pull [--rebase] upstream master
+   git pull [--rebase] upstream development
    ```
 
 6. Push your topic branch up to your fork:
@@ -189,6 +187,6 @@ Please run your code through:
    ```
 
 7. [Open a Pull Request](https://help.github.com/articles/using-pull-requests/)
-    with a clear title and description against the `master` branch. All tests must be passing before we will review the PR.
+    with a clear title and description against the `development` branch. All tests must be passing before we will review the PR.
 
 If you have any additional questions, please feel free to [email](mailto:dx@sendgrid.com) us or create an issue in this repo.