DOC: Fix links. [skip ci]
Merge pull request #1580 from jseabold/fix-links

DOC: Fix links. [skip ci]
BUG: For ARMA(0,0) ensure 1d bse and fix summary.
Merge pull request #1583 from jseabold/fix-buglet

BUG: For ARMA(0,0) ensure 1d bse and fix summary.