add valarray to documentation, update docutils on travis

Author: wjakob

.travis.yml

@@ -39,7 +39,7 @@ matrix:
   - os: linux
     language: docs
     env: DOCS STYLE LINT
-    install: pip install sphinx sphinx_rtd_theme flake8 pep8-naming
+    install: pip install --upgrade sphinx sphinx_rtd_theme flake8 pep8-naming docutils
     script:
     - make -C docs html SPHINX_OPTIONS=-W
     - tools/check-style.sh

docs/advanced/cast/overview.rst

@@ -116,6 +116,8 @@ as arguments and return values, refer to the section on binding :ref:`classes`.
 +------------------------------------+---------------------------+-------------------------------+
 | ``std::vector<T>``                 | STL dynamic array         | :file:`pybind11/stl.h`        |
 +------------------------------------+---------------------------+-------------------------------+
+| ``std::valarray<T>``               | STL value array           | :file:`pybind11/stl.h`        |
++------------------------------------+---------------------------+-------------------------------+
 | ``std::list<T>``                   | STL linked list           | :file:`pybind11/stl.h`        |
 +------------------------------------+---------------------------+-------------------------------+
 | ``std::map<T1, T2>``               | STL ordered map           | :file:`pybind11/stl.h`        |