diff --git a/.gitignore b/.gitignore
index 208da74a..87452b5d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -8,6 +8,9 @@ __pycache__/
 .cache
 .pytest_cache/
 dist/
+.tox/
+.mypy_cache/
+.hypothesis/
 
 *.so
 *.out
diff --git a/README.md b/README.md
index d6dccc38..272bf2bc 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,6 @@
 
 [![Build Status](https://travis-ci.org/PyO3/pyo3.svg?branch=master)](https://travis-ci.org/PyO3/pyo3)
 [![Build Status](https://ci.appveyor.com/api/projects/status/github/PyO3/pyo3?branch=master&svg=true)](https://ci.appveyor.com/project/fafhrd91/pyo3)
-[![codecov](https://codecov.io/gh/PyO3/pyo3/branch/master/graph/badge.svg)](https://codecov.io/gh/PyO3/pyo3)
 [![crates.io](http://meritbadge.herokuapp.com/pyo3)](https://crates.io/crates/pyo3)
 [![Join the dev chat](https://img.shields.io/gitter/room/nwjs/nw.js.svg)](https://gitter.im/PyO3/Lobby)
 
diff --git a/examples/rustapi_module/.gitignore b/examples/rustapi_module/.gitignore
deleted file mode 100644
index 7a6ac170..00000000
--- a/examples/rustapi_module/.gitignore
+++ /dev/null
@@ -1,6 +0,0 @@
-.pytest_cache
-.mypy_cache
-.hypothesis
-.tox
-
-*.py[co]
diff --git a/examples/word-count/README.md b/examples/word-count/README.md
index 0cd326fe..ff74b7de 100644
--- a/examples/word-count/README.md
+++ b/examples/word-count/README.md
@@ -24,4 +24,12 @@ There is a benchmark in `tests/test_word_count.py`:
 
 ```shell
 pytest -v tests
+```
+
+## Testing
+
+To test python 2.7, 3.5, 3.6 and 3.7, install tox globally and run 
+
+```shell
+tox
 ```
\ No newline at end of file
diff --git a/examples/word-count/requirements-dev.txt b/examples/word-count/requirements-dev.txt
new file mode 100644
index 00000000..f55c7ca8
--- /dev/null
+++ b/examples/word-count/requirements-dev.txt
@@ -0,0 +1,3 @@
+pytest>=3.5.0
+setuptools-rust>=0.10.2
+pytest-benchmark>=3.1.1
diff --git a/examples/word-count/src/lib.rs b/examples/word-count/src/lib.rs
index 166d8f30..5785a181 100644
--- a/examples/word-count/src/lib.rs
+++ b/examples/word-count/src/lib.rs
@@ -11,8 +11,8 @@ use rayon::prelude::*;
 use std::fs;
 use std::path::PathBuf;
 
-#[pyclass]
 /// Represents a file that can be searched
+#[pyclass]
 struct WordCounter {
     path: PathBuf,
 }
@@ -66,8 +66,8 @@ fn matches(word: &str, needle: &str) -> bool {
     return needle.next().is_none();
 }
 
-#[pyfunction]
 /// Count the occurences of needle in line, case insensitive
+#[pyfunction]
 fn count_line(line: &str, needle: &str) -> usize {
     let mut total = 0;
     for word in line.split(' ') {
diff --git a/examples/word-count/tox.ini b/examples/word-count/tox.ini
new file mode 100644
index 00000000..99fd941b
--- /dev/null
+++ b/examples/word-count/tox.ini
@@ -0,0 +1,14 @@
+[tox]
+envlist = py27,
+          py35,
+          py36,
+          py37,
+minversion = 3.4.0
+skip_missing_interpreters = true
+
+[testenv]
+description = Run the unit tests under {basepython}
+deps = -rrequirements-dev.txt
+usedevelop = True
+commands = pip install -e .
+           pytest tests
diff --git a/src/class/methods.rs b/src/class/methods.rs
index f3c0af89..f3ec8c2e 100644
--- a/src/class/methods.rs
+++ b/src/class/methods.rs
@@ -1,12 +1,9 @@
 // Copyright (c) 2017-present PyO3 Project and Contributors
 
-use std;
-use std::ffi::CString;
-
 use ffi;
 use libc::c_int;
-
-static NO_PY_METHODS: &'static [PyMethodDefType] = &[];
+use std;
+use std::ffi::CString;
 
 /// `PyMethodDefType` represents different types of python callable objects.
 /// It is used by `#[pymethods]` and `#[pyproto]` annotations.
@@ -123,9 +120,10 @@ impl PySetterDef {
 }
 
 #[doc(hidden)]
+/// The pymethods macro implements this trait so the methods are added to the object
 pub trait PyMethodsProtocolImpl {
     fn py_methods() -> &'static [PyMethodDefType] {
-        NO_PY_METHODS
+        &[]
     }
 }
 
@@ -134,7 +132,7 @@ impl<T> PyMethodsProtocolImpl for T {}
 #[doc(hidden)]
 pub trait PyPropMethodsProtocolImpl {
     fn py_methods() -> &'static [PyMethodDefType] {
-        NO_PY_METHODS
+        &[]
     }
 }