Fix appveyor build (cherry-pick)

So that there aren't any failures because of warnings in other modules.

.appveyor.yml

@@ -18,9 +18,9 @@ environment:
 
 install:
   - cd c:\projects
-  - curl -sSL -o boost.7z https://dl.bintray.com/boostorg/release/1.66.0/source/boost_1_66_0.7z
+  - curl -sSL -o boost.7z https://dl.bintray.com/boostorg/release/1.67.0/source/boost_1_67_0.7z
   - 7z x boost.7z
-  - set BOOST_ROOT=c:\projects\boost_1_66_0
+  - set BOOST_ROOT=c:\projects\boost_1_67_0
   - rd /s /q %BOOST_ROOT%\boost\functional\hash
   - cd %BOOST_ROOT%\tools\build
   - cmd /c bootstrap

.travis.yml

@@ -12,11 +12,11 @@ matrix:
     include:
       - compiler: gcc
         env: |
-            USER_CONFIG="using gcc : : g++-4.8 -Werror ;"
+            USER_CONFIG="using gcc : : g++-4.8 ;"
             CXXSTD=03,11
       - compiler: g++-7
         env: |
-            USER_CONFIG="using gcc : : g++-7 -Werror ;"
+            USER_CONFIG="using gcc : : g++-7 ;"
             CXXSTD=11,14,17
         addons:
           apt:
@@ -26,16 +26,16 @@ matrix:
               - ubuntu-toolchain-r-test
       - compiler: clang
         env: |
-            USER_CONFIG="using clang : : clang++ -Werror ;"
+            USER_CONFIG="using clang : : clang++ ;"
             CXXSTD=03,11
       - compiler: clang
         env: |
-            USER_CONFIG="using clang : : clang++ -Werror -D_HAS_AUTO_PTR_ETC=0 ;"
+            USER_CONFIG="using clang : : clang++ -D_HAS_AUTO_PTR_ETC=0 ;"
             CXXSTD=11
 
 before_script:
-    - export BOOST_VERSION=1.66.0
-    - export BOOST_FILENAME=boost_1_66_0
+    - export BOOST_VERSION=1.67.0
+    - export BOOST_FILENAME=boost_1_67_0
     - export BOOST_ROOT=${HOME}/boost
     - cd ${TRAVIS_BUILD_DIR}
     - touch Jamroot.jam