fix(ci): Use default build type

.travis.yml

@@ -37,7 +37,6 @@ addons:
 env:
   global:
     - BUILD_TESTS="ON"
-    - BUILD_TYPE="Release"
     - LLVM_VERSION="3.8.1"
     - LLVM_URL="http://llvm.org/releases/${LLVM_VERSION}/llvm-${LLVM_VERSION}.src.tar.xz"
     - LIBCXX_URL="http://llvm.org/releases/${LLVM_VERSION}/libcxx-${LLVM_VERSION}.src.tar.xz"

common/travis/configure.sh

@@ -5,5 +5,4 @@ cmake \
   -DCMAKE_C_COMPILER="${CC}" \
   -DCMAKE_CXX_COMPILER="${CXX}" \
   -DCMAKE_CXX_FLAGS="${CXXFLAGS}" \
-  -DCMAKE_BUILD_TYPE="${BUILD_TYPE:-Release}" \
   -DBUILD_TESTS:BOOL="${BUILD_TESTS:-OFF}" ..

common/travis/summary.sh

@@ -12,4 +12,3 @@ echo "PATH=${PATH}"
 echo "CXXFLAGS=${CXXFLAGS}"
 echo "LDFLAGS=${LDFLAGS}"
 echo "LD_LIBRARY_PATH=${LD_LIBRARY_PATH}"
-echo "BUILD_TYPE=${BUILD_TYPE}"