fix(pipfile): Fix typo in Pipfile

- python-language-server had the typo
- 'pipenv install' should work again

Author: ajyong

Pipfile

@@ -14,4 +14,4 @@ radon = "*"
 "flake8" = "*"
 httpretty = "*"
 pylint = "*"
-python-lanugage-server = {extras = ["all"],version = "*"}
+python-language-server = {extras = ["all"],version = "*"}