PYTHON-2908 Work around Jython package install problems (#733)

Author: behackett

.evergreen/config.yml

@@ -2547,7 +2547,7 @@ buildvariants:
   exclude_spec:
    # Python 3.4 doesn't support OpenSSL 1.1.0+ so won't build on Debian 9+.
    - platform: debian92
-     python-version: ["3.4"]
+     python-version: ["3.4", "jython2.7"]
      auth-ssl: "auth-ssl"
   display_name: "${python-version} OpenSSL 1.1.0 ${platform} ${auth-ssl}"
   tasks:

.evergreen/run-atlas-tests.sh

@@ -6,6 +6,9 @@ set -o xtrace
 
 export JAVA_HOME=/opt/java/jdk8
 
+# Attempt to find system pip before creating a virtualenv
+PIP=$(command -v pip2 || command -v pip)
+
 if [ -z "$PYTHON_BINARY" ]; then
     echo "No python binary specified"
     PYTHON_BINARY=$(command -v python || command -v python3) || true
@@ -28,8 +31,12 @@ else
 fi
 trap "deactivate; rm -rf atlastest" EXIT HUP
 
-if [ $IMPL = "Jython" -o $IMPL = "PyPy" ]; then
-    echo "Using Jython or PyPy"
+if [ $IMPL = "Jython" ]; then
+    echo "Using Jython"
+    $PIP download certifi
+    python -m pip install --no-index -f file://$(pwd) certifi
+elif [ $IMPL = "PyPy" ]; then
+    echo "Using PyPy"
     python -m pip install certifi
 else
     IS_PRE_279=$(python -c "import sys; sys.stdout.write('1' if sys.version_info < (2, 7, 9) else '0')")