Did the long-term capital gain/loss carryover deduction go away - it used to be on 1040 line 13?

No it's still there.  It's now on the new Schedule 1 line 13 which goes to 1040 line 6.

If you transferred your prior return it should be already filled in.

Enter a Capital Loss Carryover under
Federal Taxes or Personal (Home & Business)
Wages and Income
Then scroll down to Investment Income
Capital Loss Carryovers - Click the Start or Update button

Capital Gains and Losses now go on the new Schedule 1 line 13.  Then the total on schedule 1 line 22 gets added into 1040 line 6.  
<a rel="nofollow" target="_blank" href="https://www.irs.gov/pub/irs-pdf/f1040s1.pdf">https://www.irs.gov/pub/irs-pdf/f1040s1.pdf</a>

Thanks. I did transfer my 2017 return and it was not picked up on my 2018 return. This is the first time I used the online version of turbotax. I will probably file an amended return.