Add Tcl/Tk 8.6 to manylinux2014

[marcelotduarte]

I'm using manylinux2014 to generate wheels for cx_Freeze. As Tcl/Tk 8.5 is still used, it ended up creating an issue (https://github.com/marcelotduarte/cx_Freeze/issues/1577). So I upgrade to Tcl/Tk 8.6 in the same way as sqlite3.

[marcelotduarte]

@auvipy The build passed. But Travis returned "The job exceeded the maximum time limit for jobs, and has been terminated."

[marcelotduarte]

ping @mayeut

[mayeut]

Travis returned "The job exceeded the maximum time limit for jobs, and has been terminated."

This was just a glitch. I triggered a build on travis-ci without any cache and build times are OK.

[mayeut]

Thanks @marcelotduarte !