README: fix broken badge link.

README.md

@@ -6,7 +6,7 @@
 [![PyPI pyversions](https://img.shields.io/pypi/pyversions/pycsvy.svg)](https://pypi.python.org/pypi/pycsvy/)
 [![PyPI license](https://img.shields.io/pypi/l/pycsvy.svg)](https://pypi.python.org/pypi/pycsvy/)
 [![codecov](https://codecov.io/gh/ImperialCollegeLondon/pycsvy/branch/develop/graph/badge.svg?token=N03KYNUD18)](https://codecov.io/gh/ImperialCollegeLondon/pycsvy)
-[![Codacy Badge](https://app.codacy.com/project/badge/Grade/8d1b791b315f4814a128d94483499561)](https://www.codacy.com/gh/ImperialCollegeLondon/pycsvy/dashboard?utm_source=github.com&utm_medium=referral&utm_content=ImperialCollegeLondon/pycsvy&utm_campaign=Badge_Grade)
+[![Codacy Badge](https://app.codacy.com/project/badge/Grade/8d1b791b315f4814a128d94483499561)](https://app.codacy.com/gh/ImperialCollegeLondon/pycsvy/dashboard?utm_source=github.com&utm_medium=referral&utm_content=ImperialCollegeLondon/pycsvy&utm_campaign=Badge_Grade)
 [![pre-commit.ci status](https://results.pre-commit.ci/badge/github/ImperialCollegeLondon/pycsvy/develop.svg)](https://results.pre-commit.ci/latest/github/ImperialCollegeLondon/pycsvy/develop)
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
 [![All Contributors](https://img.shields.io/badge/all_contributors-3-orange.svg?style=flat-square)](#contributors-)