test/api: split into smaller files

Each cloud now has its own file that's sourced on-demand by the main api.sh
script. The main goal of this commit is to reduce the amount of clutter in
api.sh. I, personally, find 1300 lines of bash overwhelming and I think that
this is a reasonable beginning to start cleaning things up.

Signed-off-by: Ondřej Budai <ondrej@budai.cz>

test/cases/api/common/aws.sh

@@ -0,0 +1,23 @@
+#!/usr/bin/bash
+
+# Check that needed variables are set to access AWS.
+function checkEnv() {
+  printenv AWS_REGION AWS_BUCKET V2_AWS_ACCESS_KEY_ID V2_AWS_SECRET_ACCESS_KEY AWS_API_TEST_SHARE_ACCOUNT > /dev/null
+}
+
+function installClient() {
+  if ! hash aws; then
+    echo "Using 'awscli' from a container"
+    sudo ${CONTAINER_RUNTIME} pull ${CONTAINER_IMAGE_CLOUD_TOOLS}
+
+    AWS_CMD="sudo ${CONTAINER_RUNTIME} run --rm \
+      -e AWS_ACCESS_KEY_ID=${V2_AWS_ACCESS_KEY_ID} \
+      -e AWS_SECRET_ACCESS_KEY=${V2_AWS_SECRET_ACCESS_KEY} \
+      -v ${WORKDIR}:${WORKDIR}:Z \
+      ${CONTAINER_IMAGE_CLOUD_TOOLS} aws --region $AWS_REGION --output json --color on"
+  else
+    echo "Using pre-installed 'aws' from the system"
+    AWS_CMD="aws --region $AWS_REGION --output json --color on"
+  fi
+  $AWS_CMD --version
+}