In the case where a FK column is the PK column, don't create a new index for it; MySQL will implicitly use the PK index
To preserve FK index usage when moving an FK from PK index to an implicit one, combine index diffing clauses with the PK creation clauses
Only output an ALTER TABLE for index creation if there are indexes to create
Simplify more and fix testBuildSchema to reflect changes
Merge branch 'master' of github.com:nkiraly/DBSteward