build: Collect travis build files travis build specific directories

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

scripts/travis-install.sh

@@ -5,7 +5,10 @@
 # Stop script early on any error; check variables; be verbose
 set -eux
 
-DOWNLOAD_DIR=${PWD}/downloads
+MAIN_DIR=${PWD}
+BUILD_DIR=${PWD}/travis_build
+DOWNLOAD_DIR=${PWD}/travis_cache
+mkdir -p ${BUILD_DIR} ${DOWNLOAD_DIR}
 
 
 ######################################################################
@@ -17,9 +20,7 @@ GCC_ARM_URL="https://developer.arm.com/-/media/Files/downloads/gnu-rm/7-2017q4/g
 GCC_ARM_SHA="96a029e2ae130a1210eaa69e309ea40463028eab18ba19c1086e4c2dafe69a6a  gcc-arm-none-eabi-7-2017-q4-major-linux.tar.bz2"
 GCC_ARM_FILE="$(basename ${GCC_ARM_URL})"
 
-mkdir -p ${DOWNLOAD_DIR}
 cd ${DOWNLOAD_DIR}
-
 if [ ! -f ${GCC_ARM_FILE} ]; then
     wget "$GCC_ARM_URL"
 fi
@@ -28,7 +29,7 @@ if [ "$FOUND_SHA" != "$GCC_ARM_SHA" ]; then
     echo "ERROR: Mismatch on gcc arm sha256"
     exit -1
 fi
-cd ..
+cd ${BUILD_DIR}
 tar xf "${DOWNLOAD_DIR}/${GCC_ARM_FILE}"
 
 
@@ -37,5 +38,6 @@ tar xf "${DOWNLOAD_DIR}/${GCC_ARM_FILE}"
 ######################################################################
 
 echo "=============== Install python virtualenv"
-virtualenv python-env
-./python-env/bin/pip install cffi==1.6.0 pyserial==3.2.1 greenlet==0.4.10
+cd ${MAIN_DIR}
+virtualenv ${BUILD_DIR}/python-env
+${BUILD_DIR}/python-env/bin/pip install cffi==1.6.0 pyserial==3.2.1 greenlet==0.4.10