Remove convert(Array,d) methods to avoid warnings

[andreasnoack]

No description provided.

[andreasnoack]

This should remove the warnings messages introduced by #5545. I have removed the convert method that didn't specify the parameter value of the array. I think this is more in line with how convert works for normal arrays, since you can't do convert(Array, sub(randn(5,5),1:4,1:4)). This change required update of the parallel tests.
cc: @amitmurthy, @JeffBezanson

[amitmurthy]

Sorry for the close/reopen ! Anyway, would like Jeff/others who have a stronger understanding of Julia's Types and its intricacies to take a call on this.

[kmsquire]

@amitmurthy, what kind of call are you looking for? The current behavior is clearly wrong, as it is giving off warnings.

Since there isn't an obvious easy fix (other than this one), my suggestion is to commit this fix, and if necessary, open up a separate issue for any missing convert methods you think are needed.

[amitmurthy]

I just meant that I may not be the best judge of this PR.

Merging now. Can revert in case of any issues.

[kmsquire]

Thanks, and no worries. Sorry if I came across a bit blunt... I should probably go to bed. Cheers!