CI: B2 now uses all available cores by default

.appveyor.yml

@@ -24,7 +24,7 @@ cache:
 init:
   - set BOOST_ROOT=%APPVEYOR_BUILD_FOLDER%\..\boost
   - set BOOST_BUILD_PATH=%BOOST_ROOT%\..\boost-build
-  - set B2_ARGS=-j%NUMBER_OF_PROCESSORS% threading=multi variant=release
+  - set B2_ARGS=threading=multi variant=release
                 address-model=%ADDRMDL% toolset=%TOOLSET%
                 define=BOOST_ALL_NO_LIB
 

.travis.yml

@@ -155,7 +155,7 @@ before_install:
   - rm -rf $PROJECT
   - ./bootstrap.sh --with-toolset=clang --with-libraries=$TEST_LINK_DEPS
   - ./b2 headers
-  - ./b2 -j`nproc` threading=multi variant=release
+  - ./b2 threading=multi variant=release
       toolset=$TRAVIS_COMPILER cxxstd=${STD#*,} $STDLIB
       warnings=off
 
@@ -167,6 +167,6 @@ before_install:
   - cd $JOB
 
 script:
-  - b2 -j`nproc` threading=multi variant=release
+  - b2 threading=multi variant=release
       toolset=$TRAVIS_COMPILER cxxstd=$STD $STDLIB
       warnings=on known-warnings=suppress warnings-as-errors=on