Add Travis CI settings for Xenial and Bionic

.ci/docker/env.list

@@ -0,0 +1,7 @@
+TRAVIS_OS_NAME
+TRAVIS_PULL_REQUEST
+
+BUILD_NAME
+CC
+CXX
+SUDO

.ci/docker/ubuntu-bionic

@@ -0,0 +1,18 @@
+FROM ubuntu:bionic
+
+RUN apt-get update -qq
+RUN apt-get install -y \
+    build-essential  \
+    clang \
+    cmake \
+    curl \
+    git \
+    libgl-dev \
+    libglu-dev \
+    libpython3-dev \
+    lsb-release \
+    pkg-config \
+    python3 \
+    python3-distutils \
+    software-properties-common \
+    sudo

.ci/docker/ubuntu-xenial

@@ -0,0 +1,17 @@
+FROM ubuntu:xenial
+
+RUN apt-get update -qq
+RUN apt-get install -y \
+    build-essential  \
+    clang \
+    cmake \
+    curl \
+    git \
+    libgl-dev \
+    libglu-dev \
+    libpython3-dev \
+    lsb-release \
+    pkg-config \
+    python3 \
+    software-properties-common \
+    sudo