Bump version to 5.6.4

Author: timothycrosley

CHANGELOG.md

@@ -4,7 +4,7 @@ Changelog
 NOTE: isort follows the [semver](https://semver.org/) versioning standard.
 Find out more about isort's release policy [here](https://pycqa.github.io/isort/docs/major_releases/release_policy/).
 
-### 5.6.4 October TBD, 2020
+### 5.6.4 October 12, 2020
   - Fixed #1556: Empty line added between imports that should be skipped.
 
 ### 5.6.3 October 11, 2020

isort/_version.py

@@ -1 +1 @@
-__version__ = "5.6.3"
+__version__ = "5.6.4"

pyproject.toml

@@ -3,7 +3,7 @@ line-length = 100
 
 [tool.poetry]
 name = "isort"
-version = "5.6.3"
+version = "5.6.4"
 description = "A Python utility / library to sort Python imports."
 authors = ["Timothy Crosley <[email protected]>"]
 license = "MIT"