Apply small provisioning fixups

Pinning the gulp version fixes a build crash, and removing 'version' from
the docker-compose files resolves a warning saying that it's obsolete.

deployment/aws-batch/docker-compose.yml

@@ -1,4 +1,3 @@
-version: '2'
 services:
   update-job-defs:
       image: update-job-defs

deployment/terraform/docker-compose.yml

@@ -1,4 +1,3 @@
-version: '2'
 services:
   terraform:
     image: quay.io/azavea/terraform:1.1.9

docker-compose.test.yml

@@ -1,4 +1,3 @@
-version: '2'
 services:
   nginx:
     image: pfb-nginx:${GIT_COMMIT}

docker-compose.yml

@@ -1,4 +1,3 @@
-version: '2'
 services:
   database:
     image: postgis/postgis:13-3.1

src/angularjs/Dockerfile

@@ -10,7 +10,7 @@ RUN echo "deb http://archive.debian.org/debian stretch main" > /etc/apt/sources.
 RUN apt-get update && apt-get install -y rsync \
     && rm -rf /var/lib/apt/lists/*
 
-RUN npm install -g bower gulp
+RUN npm install -g bower gulp@3.9.0
 
 WORKDIR /opt/pfb/angularjs
 COPY package.json ${ANGULAR_DIR}/package.json