Add ability to set project branches individually or as a group via

environment variables

update.sh

 #!/bin/bash
 
 # This intended for updating the tested repos and their dependencies to the
-# latest versions before running the integration test.
+# latest versions before running the integration test. All runtime options are
+# set via environemnt variables:
+#   defaultBranch     sets branch to use for all projects
+#   clientBranch      sets branch to use for the client repository
+#   serverBranch      sets branch to use for the server repository
+#   gatewayBranch     sets branch to use for the gateway repository
+#   udbBranch         sets branch to use for the user-discovery-bot repository
+#   regBranch         sets branch to use for the registration repository
+
+# Default branch to use when no explicit project branch is set. If not set, then
+# it defaults to "master".
+default="${defaultBranch-"master"}"
+
+# Array of project names.
+project_arr=(
+  client
+  server
+  gateway
+  user-discovery-bot
+  registration
+)
+
+# Array of each project's branch. If a branch is not explicitly set via an
+# environemnt variable, then it defaults to defaultBranch.
+branch_arr=(
+  "${clientBranch-$default}"
+  "${serverBranch-$default}"
+  "${gatewayBranch-$default}"
+  "${udbBranch-$default}"
+  "${regBranch-$default}"
+)
 
 update() {
     git stash
     git clean -ffdx
-    git checkout master
+    git checkout "$1"
     git pull
-    glide cc && glide up
+    glide cache-clear && glide update
 }
 
-for DIR in client server gateway user-discovery-bot registration; do
-    echo $DIR
-    pushd $GOPATH/src/gitlab.com/elixxir/client
-    update
+for ((i=0; i<${#project_arr[@]}; ++i)); do
+    printf "\n\033[1m%s\033[0m\n" "${project_arr[i]}"
+    pushd "$GOPATH"/src/gitlab.com/elixxir/client || exit
+    update "${branch_arr[i]}"
     go test ./...
-    popd
+    popd || exit
 done