add missing vars for python step

bin/compile

@@ -60,7 +60,7 @@ LATEST_2="python-2.7.15"
 PY37="python-3.7"
 PY36="python-3.6"
 PY35="python-3.5"
-PY35="python-3.4"
+PY34="python-3.4"
 PY27="python-2.7"
 
 # Which stack is used (for binary downloading), if none is provided (e.g. outside of Heroku)?
@@ -68,8 +68,9 @@ DEFAULT_PYTHON_STACK="cedar-14"
 # If pip doesn't match this version (the version we install), run the installer.
 PIP_UPDATE="9.0.2"
 
-export DEFAULT_PYTHON_VERSION DEFAULT_PYTHON_STACK PIP_UPDATE LATEST_2 LATEST_36 LATEST_37
-export PY37 PY36 PY35 PY27
+export DEFAULT_PYTHON_VERSION DEFAULT_PYTHON_STACK PIP_UPDATE
+export LATEST_2 LATEST_36 LATEST_37 LATEST_35 LATEST_34
+export PY37 PY36 PY35 PY27 PY34
 
 # Common Problem Warnings:
 # This section creates a temporary file in which to stick the output of `pip install`.

bin/steps/python

@@ -52,7 +52,6 @@ else
   exit 1
 fi
 
-
 if [[ "$STACK" != "$CACHED_PYTHON_STACK" ]]; then
     puts-step "Stack has changed from $CACHED_PYTHON_STACK to $STACK, clearing cache"
     rm -fr .heroku/python-stack .heroku/python-version .heroku/python .heroku/vendor .heroku/python .heroku/python-sqlite3-version