Add script to fetch correct dep branches

Fetch branches of js-sdk and react-sdk that match the current
branch name, if they exist. This will mostly be used in the
automated tests.

scripts/fetch-develop.deps.sh

@@ -0,0 +1,25 @@
+#!/bin/sh
+
+# Fetches the js-sdk and matrix-react-sdk dependencies for development
+# or testing purposes
+# If there exists a branch of that dependency with the same name as
+# the branch the current checkout is on, use that branch. Otherwise,
+# use develop.
+
+curbranch=`git rev-parse --abbrev-ref HEAD`
+
+cd node_modules
+
+function dodep() {
+    org=$1
+    repo=$2
+    rm -rf $repo || true
+    git clone https://github.com/$org/$repo.git $repo
+    pushd $repo
+    git checkout $curbranch || git checkout develop
+    echo "$repo set to branch "`git rev-parse --abbrev-ref HEAD`
+    popd
+}
+
+dodep matrix-org matrix-js-sdk
+dodep matrix-org matrix-react-sdk