Merge pull request #75 from josesho/master

add instructions for which branch to PR into

CONTRIBUTING.md

@@ -1,14 +1,19 @@
 # Contributing to DABEST-Python
 
+
 ## Did you find a bug?
 - Ensure the bug was not already reported by searching in [Issues](https://github.com/ACCLAB/DABEST-python/issues). Check that the bug hasn't been addressed in a closed issue.
 
 - If the bug isn't being addressed, open a new one. Be sure to include a title and clear description, and a [minimally reproducible code sample](https://matthewrocklin.com/blog/work/2018/02/28/minimal-bug-reports) demonstrating the expected behavior that is not occurring. 
 
+
 ## Did you write a patch that fixes a bug?
-- Open a new GitHub pull request with the patch.
+- Open a new GitHub [pull request](https://help.github.com/en/articles/about-pull-requests)(PR for short) with the patch.
+
+- Create the PR into the development branch, which is indicated by `v{latest version number}_dev`.
+
+- Clearly state the problem and solution in the PR description. Include the relevant [issue number](https://guides.github.com/features/issues/) if applicable.
 
-- Ensure the PR description clearly describes the problem and solution. Include the relevant issue number if applicable.
 
 ## Do you intend to add a new feature or change an existing one?
 - Suggest your change by opening an issue, and adding an Enhancement tag.