Fix invalid tox syntax (#293)

tox.ini

@@ -1,27 +1,27 @@
-[tox]
-envlist = py{37,38,39,310},pycodestyle
-
-[pycodestyle]
-max-line-length = 120
-
-[pytest]
-# Disable running benchmarks by default
-# (tests still run but no benchmarking done)
-addopts = --benchmark-disable
-
-[testenv]
-deps =
-    pytest
-    coverage
-passenv = CI GITHUB_* RUNNER_*
-extras = test,pandas,hdf,thermocouple_scaling
-commands =
-    coverage run -m pytest []
-    coverage report
-    coverage xml
-
-[testenv:pycodestyle]
-skip_install = True
-deps = pycodestyle
-commands =
-    pycodestyle ./nptdms
+[tox]
+envlist = py{37,38,39,310},pycodestyle
+
+[pycodestyle]
+max-line-length = 120
+
+[pytest]
+# Disable running benchmarks by default
+# (tests still run but no benchmarking done)
+addopts = --benchmark-disable
+
+[testenv]
+deps =
+    pytest
+    coverage
+passenv = CI,GITHUB_*,RUNNER_*
+extras = test,pandas,hdf,thermocouple_scaling
+commands =
+    coverage run -m pytest []
+    coverage report
+    coverage xml
+
+[testenv:pycodestyle]
+skip_install = True
+deps = pycodestyle
+commands =
+    pycodestyle ./nptdms