Python 2.7.16 (#808)

* new recipe for new runtime

* add new runtime formula

* wrangle tests into submission

builds/runtimes/python-2.7.16

+#!/usr/bin/env bash
+# Build Path: /app/.heroku/python/
+
+OUT_PREFIX=$1
+BIN_DIR="$(cd "$(dirname "$0")"/../.. || exit; pwd)/bin"
+export BIN_DIR
+
+# shellcheck source=bin/utils
+source "$BIN_DIR/steps/sqlite3"
+
+sqlite3_version
+echo "Setting up SQLite3 Headers for $SQLITE3_VERSION"
+sqlite3_install "$OUT_PREFIX" "$SQLITE3_VERSION" 1
+
+echo "Building Python…"
+SOURCE_TARBALL='https://python.org/ftp/python/2.7.16/Python-2.7.16.tgz'
+curl -L $SOURCE_TARBALL | tar xz
+mv Python-2.7.16 src
+cd src
+
+./configure --prefix=$OUT_PREFIX  --enable-unicode=ucs4 --with-ensurepip=no
+make
+make install
+
+# Remove unneeded test directories, similar to the official Docker Python images:
+# https://github.com/docker-library/python
+find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +

test/fixtures/python2_fail/runtime.txt

-python-2.7.16
+python-2.7.99