Add changelog for version 0.3.1

CHANGELOG.md

@@ -1,5 +1,27 @@
 # History of changes
 
+## Version 0.3.1 (2018/06/15)
+
+This version fixes some bugs and also includes some cosmetic changes.
+
+### Issues Closed
+
+* [Issue 117](https://github.com/spyder-ide/spyder-unittest/issues/117) - Rename "py.test" to "pytest" throughout ([PR 119](https://github.com/spyder-ide/spyder-unittest/pull/119))
+* [Issue 113](https://github.com/spyder-ide/spyder-unittest/issues/113) - NameError in test file causes internal error ([PR 118](https://github.com/spyder-ide/spyder-unittest/pull/118))
+* [Issue 112](https://github.com/spyder-ide/spyder-unittest/issues/112) - Plugin confused by tests writing to sys.__stdout__ ([PR 114](https://github.com/spyder-ide/spyder-unittest/pull/114))
+
+In this release 3 issues were closed.
+
+### Pull Requests Merged
+
+* [PR 121](https://github.com/spyder-ide/spyder-unittest/pull/121) - PR: Update readme to remove funding appeal, harmonize with other readmes and minor fixes ([](a few obvious bugs/typos in the text. You can preview the full changes live over on [my repo](https://github.com/CAM-Gerlach/spyder-unittest/blob/update-readme/issues/))
+* [PR 120](https://github.com/spyder-ide/spyder-unittest/pull/120) - Remove unused variables when initializing localization
+* [PR 119](https://github.com/spyder-ide/spyder-unittest/pull/119) - Replace 'py.test' by 'pytest' ([117](https://github.com/spyder-ide/spyder-unittest/issues/117))
+* [PR 118](https://github.com/spyder-ide/spyder-unittest/pull/118) - Use str() to convert pytest's longrepr to a string ([113](https://github.com/spyder-ide/spyder-unittest/issues/113))
+* [PR 114](https://github.com/spyder-ide/spyder-unittest/pull/114) - Use ZMQ sockets to communicate results of pytest run ([112](https://github.com/spyder-ide/spyder-unittest/issues/112))
+
+In this release 5 pull requests were closed.
+
 ## Version 0.3.0 (2018/02/16)
 
 This version includes improved support of `py.test` (test results are displayed as they come in, double clicking on a test result opens the test in the editor) as well as various other improvements.
@@ -114,4 +136,4 @@ In this release 1 pull request was closed.
 
 ## Version 0.1.0 (2017/02/05)
 
-Initial release, supporting nose and py.test frameworks.
+Initial release, supporting nose and py.test frameworks.