Add PR template (#17)

.github/pull_request_template.md

@@ -0,0 +1,42 @@
+<!--
+Thanks for contributing!
+
+About this template:
+The following template aims to help contributors write a good description
+for their pull requests.
+We'd like you to provide a description of the changes in your pull request 
+(i.e. bugs fixed or features added), motivation behind the changes, and 
+complete the checklist below before opening a pull request.
+
+Feel free to discard it if you need to (e.g. when you just fix a typo). -->
+
+# Motivation / Background
+
+<!--
+Describe why this Pull Request needs to be merged. What bug have you fixed? 
+What feature have you added? Why is it important?
+If you are fixing a specific issue, include "Fixes #ISSUE" (replace 
+with the issue number, remove the quotes) and the issue will be linked
+to this PR.
+-->
+
+This Pull Request has been created because...
+
+## Additional information
+
+<!-- Provide additional information such as benchmarks, reference to 
+other repositories or alternative 
+solutions. -->
+
+# Checklist
+
+Before submitting the PR, make sure the following are checked:
+
+- [ ] Version file (/.version) is updated according to the
+[Semantic Version](https://semver.org/) rules.
+- [ ] This Pull Request is related to one change.
+Changes that are unrelated should be opened in separate PRs.
+- [ ] Commit message has a detailed description of what changed and why.
+If this PR fixes a related issue, include it in the commit message.
+Ex: _[Fixes #issue-number]_.
+- [ ] Tests are added or updated if you fix a bug or add a feature.

.version

@@ -1 +1 @@
-0.3.0
+0.3.1