ci: remove travis.yml

Signed-off-by: Fabio Utzig <fabio.utzig@nordicsemi.no>
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index 95ffb4d..0000000
--- a/.travis.yml
+++ /dev/null
@@ -1,76 +0,0 @@
-# Travis configuration.  Build the simulator and run its tests.
-
-addons:
-  apt:
-    packages:
-      - "python3-pip"
-
-language: rust
-
-cache:
-  directories:
-    - $HOME/TOOLCHAIN
-    - cargo
-
-matrix:
-  include:
-    # Runs each value defined in $SINGLE_FEATURES by itself in the order
-    # the were defined.
-    # - os: linux
-    #   env: SINGLE_FEATURES="sig-ecdsa sig-ed25519 enc-kw bootstrap" TEST=sim
-    # - os: linux
-    #   env: SINGLE_FEATURES="none sig-rsa sig-rsa3072 overwrite-only validate-primary-slot swap-move" TEST=sim
-    # - os: linux
-    #   env: SINGLE_FEATURES="enc-rsa enc-ec256 enc-x25519" TEST=sim
-
-    # Values defined in $MULTI_FEATURES consist of any number of features
-    # to be enabled at the same time. The list of multi-values should be
-    # separated by ',' and each list of values is run sequentially in the
-    # defined order.
-    # - os: linux
-    #   env: MULTI_FEATURES="sig-rsa overwrite-only large-write,sig-ecdsa overwrite-only large-write,multiimage overwrite-only large-write" TEST=sim
-    # - os: linux
-    #   env: MULTI_FEATURES="sig-rsa validate-primary-slot,sig-ecdsa validate-primary-slot,sig-rsa multiimage validate-primary-slot" TEST=sim
-    # - os: linux
-    #   env: MULTI_FEATURES="enc-kw overwrite-only large-write,enc-rsa overwrite-only large-write" TEST=sim
-    # - os: linux
-    #   env: MULTI_FEATURES="sig-rsa enc-rsa validate-primary-slot,swap-move enc-rsa sig-rsa validate-primary-slot" TEST=sim
-    # - os: linux
-    #   env: MULTI_FEATURES="sig-rsa enc-kw validate-primary-slot bootstrap,sig-ed25519 enc-x25519 validate-primary-slot" TEST=sim
-    # - os: linux
-    #   env: MULTI_FEATURES="sig-ecdsa enc-kw validate-primary-slot" TEST=sim
-    # - os: linux
-    #   env: MULTI_FEATURES="sig-rsa validate-primary-slot overwrite-only large-write,sig-ecdsa enc-ec256 validate-primary-slot" TEST=sim
-    # - os: linux
-    #   env: MULTI_FEATURES="sig-rsa validate-primary-slot overwrite-only downgrade-prevention" TEST=sim
-
-    # - os: linux
-    #   language: go
-    #   env: TEST=mynewt
-    #   go:
-    #     - "1.12"
-
-    - os: linux
-      language: python
-      env: TEST=imgtool
-
-before_install:
-  - |
-    if [ "$TRAVIS_PULL_REQUEST" != "false" ]; then
-      ./ci/check-signed-off-by.sh
-      if [ $? -ne 0 ]; then
-        exit 1
-      fi
-    fi
-
-install:
-  - ./ci/${TEST}_install.sh
-
-script:
-  - ./ci/${TEST}_run.sh
-
-notifications:
-  slack:
-    rooms:
-      - secure: "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"
-    on_success: always