Download pypy-nightly (trunk and py3.6) and install to virtualenvs in ~/.virtualenvs

## pypy-nightly.sh
#!/bin/bash
set -e

# Download pypy nightly builds and create virtualenvs
BRANCHES=(trunk py3.6)

for BRANCH in "${BRANCHES[@]}"
do
  DEST_DIR=~/pypy-nightly/${BRANCH}
  VENV=~/.virtualenvs/pypy-nightly-${BRANCH}
  PLATFORM=linux64
  VARIANT=pypy-c-jit
  BUILD=${VARIANT}-latest-${PLATFORM}
  BUILD_ARTIFACT=${BUILD}.tar.bz2
  BUILD_URL=http://buildbot.pypy.org/nightly/${BRANCH}/${BUILD_ARTIFACT}

  mkdir -p ${DEST_DIR}
  cd ${DEST_DIR}

  if [ -f "${BUILD_ARTIFACT}" ]; then
    # Curls -z "Resume" trumps -I "If-Modified" - delete previous file manually.
    LAST_MODIFIED=$(date +%s --date="`curl -sI ${BUILD_URL} | grep 'Last-Modified' | cut -c16-`")
    LAST_DOWNLOADED=$(stat -c %Y ${BUILD_ARTIFACT})
    if [ $LAST_MODIFIED -gt $LAST_DOWNLOADED ]; then
        rm ${BUILD_ARTIFACT} | /bin/true
    fi
  fi

  CURL_ARGS="-#LOC - ${BUILD_URL}"
  if [ -f "${BUILD_ARTIFACT}" ]; then
      CURL_ARGS="-z ${BUILD_ARTIFACT} ${CURL_ARGS}"
  fi
  curl ${CURL_ARGS}

  tar -jxpf ${BUILD_ARTIFACT}
  ln `tar -tf ${BUILD_ARTIFACT} | head -1` ${BUILD} -sf
  echo Extracted ${BRANCH}/$(readlink ${BUILD})
  set -- ${DEST_DIR}/${BUILD}/bin/pypy*
  PYPY_BIN=$1
  /usr/bin/virtualenv ${VENV} -p ${PYPY_BIN} -q --clear | true
done