Update .gitignore file to ignore IntelliJ IDEA files

Test: git status to make sure the files do not appear

Change-Id: I25cd8f7453bfbf44cd5020682dca655e0c8585a6
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..98b50ee
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+# IntelliJ IDEA
+.idea/
+*.iml