psutil install fails on debian8 build

[rallytime]

When running a docker build -t salt-debian8 . command, the build exits because psutil can't be installed:

  Running setup.py install for psutil: started
    Running setup.py install for psutil: finished with status 'error'
    Complete output from command /usr/bin/python -u -c "import setuptools, tokenize;__file__='/tmp/pip-build-xEsNOj/psutil/setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record /tmp/pip-B2tkIC-record/install-record.txt --single-version-externally-managed --compile:
    running install
    running build
    running build_py
    creating build
    creating build/lib.linux-x86_64-2.7
    creating build/lib.linux-x86_64-2.7/psutil
    copying psutil/_pslinux.py -> build/lib.linux-x86_64-2.7/psutil
    copying psutil/_pssunos.py -> build/lib.linux-x86_64-2.7/psutil
    copying psutil/_psbsd.py -> build/lib.linux-x86_64-2.7/psutil
    copying psutil/_common.py -> build/lib.linux-x86_64-2.7/psutil
    copying psutil/__init__.py -> build/lib.linux-x86_64-2.7/psutil
    copying psutil/_pswindows.py -> build/lib.linux-x86_64-2.7/psutil
    copying psutil/_psosx.py -> build/lib.linux-x86_64-2.7/psutil
    copying psutil/_psposix.py -> build/lib.linux-x86_64-2.7/psutil
    copying psutil/_compat.py -> build/lib.linux-x86_64-2.7/psutil
    creating build/lib.linux-x86_64-2.7/psutil/tests
    copying psutil/tests/test_linux.py -> build/lib.linux-x86_64-2.7/psutil/tests
    copying psutil/tests/test_process.py -> build/lib.linux-x86_64-2.7/psutil/tests
    copying psutil/tests/__init__.py -> build/lib.linux-x86_64-2.7/psutil/tests
    copying psutil/tests/test_bsd.py -> build/lib.linux-x86_64-2.7/psutil/tests
    copying psutil/tests/test_misc.py -> build/lib.linux-x86_64-2.7/psutil/tests
    copying psutil/tests/test_system.py -> build/lib.linux-x86_64-2.7/psutil/tests
    copying psutil/tests/test_windows.py -> build/lib.linux-x86_64-2.7/psutil/tests
    copying psutil/tests/runner.py -> build/lib.linux-x86_64-2.7/psutil/tests
    copying psutil/tests/test_posix.py -> build/lib.linux-x86_64-2.7/psutil/tests
    copying psutil/tests/test_sunos.py -> build/lib.linux-x86_64-2.7/psutil/tests
    copying psutil/tests/test_osx.py -> build/lib.linux-x86_64-2.7/psutil/tests
    copying psutil/tests/test_memory_leaks.py -> build/lib.linux-x86_64-2.7/psutil/tests
    running build_ext
    building 'psutil._psutil_linux' extension
    creating build/temp.linux-x86_64-2.7
    creating build/temp.linux-x86_64-2.7/psutil
    x86_64-linux-gnu-gcc -pthread -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes -fno-strict-aliasing -D_FORTIFY_SOURCE=2 -g -fstack-protector-strong -Wformat -Werror=format-security -fPIC -DPSUTIL_VERSION=431 -I/usr/include/python2.7 -c psutil/_psutil_linux.c -o build/temp.linux-x86_64-2.7/psutil/_psutil_linux.o
    psutil/_psutil_linux.c:12:20: fatal error: Python.h: No such file or directory
     #include <Python.h>
                        ^
    compilation terminated.
    error: command 'x86_64-linux-gnu-gcc' failed with exit status 1

    ----------------------------------------
Command "/usr/bin/python -u -c "import setuptools, tokenize;__file__='/tmp/pip-build-xEsNOj/psutil/setup.py';exec(compile(getattr(tokenize, 'open', open)(__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" install --record /tmp/pip-B2tkIC-record/install-record.txt --single-version-externally-managed --compile" failed with error code 1 in /tmp/pip-build-xEsNOj/psutil/
INFO[0009] The command [/bin/sh -c pip install -r /dev_python27.txt] returned a non-zero code: 1