Compare docker versions

    >>> v1 = '1.9'
    >>> v2 = '1.10'
    >>> compare_version(v1, v2)
    1
    >>> compare_version(v2, v1)
    -1
    >>> compare_version(v2, v2)
    0

def compare_version(v1, v2):
    """Compare docker versions

    >>> v1 = '1.9'
    >>> v2 = '1.10'
    >>> compare_version(v1, v2)
    1
    >>> compare_version(v2, v1)
    -1
    >>> compare_version(v2, v2)
    0
    """
    s1 = StrictVersion(v1)
    s2 = StrictVersion(v2)
    if s1 == s2:
        return 0
    elif s1 > s2:
        return -1
    else:
        return 1