travis-ci: Removing travis-ci config

We are replacing this with an internally run gitlab-ci instance, so no
need to keep this file.

.travis.yml

@@ -1,26 +0,0 @@
-sudo: required
-dist: trusty
-language: c
-before_install:
-  - sudo add-apt-repository ppa:bitcoin/bitcoin -y
-  - sudo add-apt-repository ppa:ondrej/pkg-nlnetlabs -y || true # This fails due to UTF-8 in the author's name...
-  - sudo add-apt-repository ppa:chris-lea/libsodium -y
-  - sudo apt-get -qq update
-install:
-  - sudo apt-get install -y --no-install-recommends bitcoind build-essential automake eatmydata net-tools libtool libprotobuf-c-dev libsodium-dev libsqlite3-dev valgrind protobuf-c-compiler libgmp-dev
-  - git clone https://github.com/luke-jr/libbase58.git libbase58; cd libbase58; ./autogen.sh; ./configure; make; sudo make install; cd ..
-  - git clone https://github.com/rustyrussell/lightning-rfc.git ../lightning-rfc
-compiler:
-  - gcc
-script:
-  - make clean
-  - make
-  - make full-check
-after_failure:
-  - sudo killall lightningd
-  - sudo kill `ps aux | grep lightningd | grep -v grep | awk '{print $2}'`;
-  - tar -cvjf /tmp/travis-run.tar.bz2 /tmp/lightning.*.?;
-  - curl --upload-file /tmp/travis-run.tar.bz2 https://transfer.sh/travis-run.tar.bz2;
-env:
-  global:
-    - LD_LIBRARY_PATH=/usr/local/lib