TX: Dublin bypass

[yakra]

The Dublin bypass opened in October 2015.

http://www.dublincitizen.com/articles/2015/10/14/bypass-opens-monday
http://www.dublincitizen.com/articles/2015/10/21/dublin-loop-now-open

Now that the second half is completed, TxDOT retires State Highway 267, the temporary designation of the first half.
The loop now becomes a portion of U.S. 67/ Highway 377 while  the  section running through Dublin is Business U.S. 67/ Highway 377.

http://www.dublincitizen.com/articles/2015/11/04/one-dies-bypass-wreck "was turning off of Business 67"

Files affected:
US67: relocate
US377: relocate
US67BusDub: add
US377BusDub: add? Not in TXDOT designation files. AASHTO May 2013: applied for US67Bus only. Dublin Citizen says yes. Precedent: US81Bus/287Bus; Rho, Dec or Alv. What the hey. Adding it.
TX6: relabel points
TX167: relabel points
TX267: delete. 0 total drivers.
usatx.csv: delete TX267
usatx_con.csv: delete TX267
usausb.csv: add US67BusDub & US377BusDub
usausb_con.csv: add US67BusDub & US377BusDub

https://github.com/TravelMapping/HighwayData/pull/932