Use aws lambda image

Dockerfile

@@ -1,28 +1,19 @@
-FROM amazonlinux:2
-
+FROM amazon/aws-lambda-python:3.8
 # Need to set "ulimit -n" to a small value to stop yum from hanging:
 # https://bugzilla.redhat.com/show_bug.cgi?id=1715254#c1
 # See the following for installing 3.8 via yum on amazon-linux
 # https://techviewleo.com/how-to-install-python-on-amazon-linux/
-RUN ulimit -n 1024 \
-	&& amazon-linux-extras enable python3.8 && yum clean metadata \
-	&& yum -y update && yum -y install \
+RUN ulimit -n 1024 && yum -y update && yum -y install \
 	  git \
 	  gcc \
-	  python38 \
-	  python38-devel \
 	  jq \
 	  nano \
 	  unzip \
 	  zip \
 	  && yum clean all
 
-RUN update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.8 1
-
 COPY requirements.txt quilt/requirements.txt
 
-RUN python3 -m pip install pip==21.1.1
-
 # Requirements copied from lambda Python 3.6, but not in base image
 # (Plus Cython which is a build-time requirement for numpy)
 RUN python3 -m pip install -r quilt/requirements.txt