Fix autodoc

[barryytm]

Closes #80

Update Sphinx to 1.6.6 to fix the build

Tested build: http://fgpv-vpgf.github.io/rcs/doctest/

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This change is 

[alyec]

Docutils is now at 0.14 and ahccd is able to build without downgrading. Can you look at updating either docutils to 0.14 or sphinx itself?

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Review status: 0 of 2 files reviewed at latest revision, all discussions resolved.

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Comments from Reviewable

[barryytm]

Update Sphinx to 1.6.6 worked. Tested build: http://fgpv-vpgf.github.io/rcs/doctest/

[alyec]

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Reviewed 1 of 2 files at r1, 1 of 2 files at r2.
Review status: all files reviewed at latest revision, all discussions resolved.

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Comments from Reviewable

[james-rae]

Reviewed 1 of 2 files at r1, 1 of 2 files at r2.
Review status: all files reviewed at latest revision, all discussions resolved, all commit checks successful.

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Comments from Reviewable