test on centos7 via docker

.dockerignore

@@ -2,3 +2,4 @@
 .gitignore
 .git
 Dockerfile
+Dockerfile.centos7

.travis.yml

@@ -6,7 +6,20 @@ sudo: false
 
 matrix:
   include:
-    # test on docker
+    # test on docker+centos7
+    - os: linux
+      compiler: clang
+      services:
+       - docker
+      sudo: true
+      dist: trusty
+      env: DOCKERFILE=Dockerfile.centos7
+      before_install: []
+      install:
+        - docker build -t tippecanoe-image -f ${DOCKERFILE} .
+      script:
+        - docker run -it tippecanoe-image
+    # test on docker+ubuntu
     - os: linux
       compiler: clang
       services:

Dockerfile

@@ -15,5 +15,5 @@ COPY . /tmp/tippecanoe-src
 RUN make \
   && make install
 
-# Run the default command to show usage
+# Run the tests
 CMD make test

Dockerfile.centos7

@@ -0,0 +1,15 @@
+FROM centos:7
+
+RUN yum install -y make sqlite-devel zlib-devel bash git gcc-c++
+
+# Create a directory and copy in all files
+RUN mkdir -p /tmp/tippecanoe-src
+WORKDIR /tmp/tippecanoe-src
+COPY . /tmp/tippecanoe-src
+
+# Build tippecanoe
+RUN make \
+  && make install
+
+# Run the tests
+CMD make test