TT#82051 build: Remove unused .travis.yml file

The Travis service got closed down, and is no longer being used.

Change-Id: I547258a6ab0981eacb9933b62abead13fa8e0282

.travis.yml

@@ -1,20 +0,0 @@
-language: c
-compiler:
-  - gcc
-  - clang
-before_install:
-  - sudo apt-get update
-  - sudo apt-get -y install devscripts equivs
-  # workarounds for Ubuntu xenial/16.04 LTS,
-  # `apt-get -y build-dep -Ppkg.ngcp-rtpengine.nobcg729 .`
-  # as well as several Build-Deps aren't available
-  - sed -i '/libbcg729-dev/d' debian/control
-  - sed -i 's/default-libmysqlclient-dev/libmysqlclient-dev/' debian/control
-  - sed -i 's/libiptc-dev/iptables-dev/' debian/control
-  - sed -i 's/debhelper-compat.*/debhelper,/' debian/control
-  - mk-build-deps --build-dep --install --remove --root-cmd sudo
-script:
-  - make -C iptables-extension
-    # `dpkg-parsechangelog [...] -STimestamp` is not available
-    # on Ubuntu xenial/16.04 LTS
-  - RELEASE_DATE=travis-$(date +%s) make -C daemon -j$(nproc)