Update Travis Tests to run platforms in parallel (#11256)

buildroot/share/tests/start_tests

@@ -0,0 +1,37 @@
+#!/usr/bin/env bash
+export PATH="$PATH:$( cd "$(dirname "${BASH_SOURCE[0]}")" ; pwd -P )"
+export PATH="$PATH:./buildroot/bin"
+
+# exit on first failure
+set -e
+
+exec_test () {
+  printf "\033[0;32m[Test $2] \033[0m$3... "
+  if build_marlin_pio $1 "-e $2"; then
+    printf "\033[0;32mPassed\033[0m\n"
+    return 0
+  else
+    env_restore
+    printf "\033[0;31mFailed!\033[0m\n"
+    return 1
+  fi
+}
+export -f exec_test
+
+env_backup
+printf "Running \033[0;32m$2\033[0m Tests\n"
+if [ $2 = "ALL" ]; then
+  dir_list=("$(dirname "${BASH_SOURCE[0]}")"/*)
+  declare -a tests=(${dir_list[@]/*start_tests/})
+  for f in "${tests[@]}"; do
+    testenv=$(basename $f | cut -d"_" -f1)
+    printf "Running \033[0;32m$f\033[0m Tests\n"
+    exec_test $1 "$testenv --target clean" "Setup Build Environment"
+    $f $1 $testenv
+  done
+else
+  exec_test $1 "$2 --target clean" "Setup Build Environment"
+  $2_tests $1 $2
+fi
+printf "\033[0;32mAll tests completed successfully\033[0m\n"
+env_restore