Updated Dockerfile for 14.04 to 3.7.
Updated Dockerfile for 14.04 to 3.7.

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jsyeo/rubinius,kachick/rubinius,kachick/rubinius,jsyeo/rubinius,jsyeo/rubinius,jsyeo/rubinius,kachick/rubinius,kachick/rubinius,kachick/rubinius,kachick/rubinius,jsyeo/rubinius,jsyeo/rubinius,jsyeo/rubinius,kachick/rubinius,kachick/rubinius