diff --git a/.gitignore b/.gitignore
index c7af290..ce77503 100644
--- a/.gitignore
+++ b/.gitignore
@@ -55,3 +55,4 @@ target/
 
 venv/
 .DS_Store
+.idea/
diff --git a/.python-version b/.python-version
new file mode 100644
index 0000000..d15b8b0
--- /dev/null
+++ b/.python-version
@@ -0,0 +1 @@
+3.6.5
diff --git a/Makefile b/Makefile
index 694d76b..bbaf14a 100644
--- a/Makefile
+++ b/Makefile
@@ -48,6 +48,7 @@ clean:
 	rm -f .coverage
 	rm -rf coverage
 	rm -rf build
+	rm -rf venv
 
 
 .PHONY: all build env linux run pep test vtest testloop cov clean
diff --git a/requirements.txt b/requirements.txt
index 2201413..cb9eaa5 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1 +1 @@
-mistune==0.7
+mistune==0.7.3