add pipenv rebuild script

dev/docker/Dockerfile

@@ -7,6 +7,7 @@ RUN apt-get update -y && apt-get upgrade -y && apt-get install gcc libffi-dev wg
 
 # make an install directory
 RUN mkdir /install
+WORKDIR /install
 
 # copy only the exact files needed for install into the container
 COPY ./nucypher/__about__.py /install/nucypher/

scripts/installation/rebuild_pipenv.sh

@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+
+read -p "Ok if we update your pip and setuptools? (type y or Y) " -n 1 -r
+echo 
+if [[ $REPLY =~ ^[Yy]$ ]]
+then
+    pip install --upgrade pip
+    pip install --upgrade setuptools
+fi
+
+rm requirements.txt
+rm dev-requirements.txt
+
+touch requirements.txt
+touch dev-requirements.txt
+
+set -e 
+echo "rebuilding pipenv.lock... this will take awhile."
+pipenv lock --clear
+
+pipenv lock -r > requirements.txt
+pipenv lock -r --dev > dev-requirements.txt
+
+