gnucash maint: Remove Travis CI.

[John Ralls]

Updated	 via  https://github.com/Gnucash/gnucash/commit/3a323ec5 (commit)
	from  https://github.com/Gnucash/gnucash/commit/c2ba88d9 (commit)



commit 3a323ec59ff2eb6d3384a1457cb732f9e0c680dc
Author: John Ralls <jralls at ceridwen.us>
Date:   Mon Dec 14 09:13:54 2020 -0800

    Remove Travis CI.
    
    It has become unreliable and will cease providing free access soon.



Summary of changes:
 .travis.yml                     | 15 ---------------
 util/ci/afterfailure            | 13 -------------
 util/ci/arch-docker             |  9 ---------
 util/ci/arch-testscript         |  9 ---------
 util/ci/commonbuild             | 21 ---------------------
 util/ci/ubuntu-18.04-docker     | 18 ------------------
 util/ci/ubuntu-18.04-testscript |  6 ------
 7 files changed, 91 deletions(-)
 delete mode 100644 .travis.yml
 delete mode 100755 util/ci/afterfailure
 delete mode 100644 util/ci/arch-docker
 delete mode 100644 util/ci/arch-testscript
 delete mode 100644 util/ci/commonbuild
 delete mode 100644 util/ci/ubuntu-18.04-docker
 delete mode 100644 util/ci/ubuntu-18.04-testscript