Circle CI: Test build with C++17 and C++14

circle.yml

@@ -3,7 +3,7 @@ jobs:
 
   lint:
     docker:
-    - image: ethereum/cpp-build-env
+    - image: ethereum/cpp-build-env:7
     steps:
     - checkout
     - run:
@@ -18,15 +18,15 @@ jobs:
           sudo pip3 install codespell
           codespell --quiet-level=4 --ignore-words=./.codespell-whitelist
 
-  build: &build
+  build-cxx11: &build
     docker:
-      - image: ethereum/cpp-build-env
+      - image: ethereum/cpp-build-env:7
     steps:
       - checkout
       - run:
           name: "Configure"
           working_directory: ~/build
-          command: cmake ../project -DCMAKE_INSTALL_PREFIX=~/install -DBUILD_SHARED_LIBS=ON -DEVMC_EXAMPLES=ON -DEVMC_TESTING=ON
+          command: cmake ../project -DCMAKE_INSTALL_PREFIX=~/install -DBUILD_SHARED_LIBS=ON -DEVMC_EXAMPLES=ON -DEVMC_TESTING=ON $CMAKE_OPTIONS
       - run:
           name: "Build"
           command: cmake --build ~/build
@@ -63,11 +63,19 @@ jobs:
           name: "Run evmc-vmtester libevmc-example-vm.so"
           command: ~/install/bin/evmc-vmtester ~/install/lib/libevmc-example-vm.so
 
-  build-clang-3.8:
+  build-cxx14:
     <<: *build
     environment:
       CC: clang-3.8
       CXX: clang++-3.8
+      CMAKE_OPTIONS: -DTOOLCHAIN=cxx14-pic
+
+  build-cxx17:
+    <<: *build
+    environment:
+      CC: gcc-6
+      CXX: g++-6
+      CMAKE_OPTIONS: -DTOOLCHAIN=cxx17-pic
 
   test-docs:
     docker:
@@ -133,8 +141,9 @@ workflows:
   evmc:
     jobs:
       - lint
-      - build
-      - build-clang-3.8
+      - build-cxx11
+      - build-cxx14
+      - build-cxx17
       - bindings-go-1.11
       - bindings-go-1.10
       - bindings-go-1.9