CHORE: add .gitignore file

Refs: #15

.gitignore

+
+##### Log files
+*.log
+
+##### Vagrant
+.vagrant
+
+##### GIT
+
+# Git - Merge temp file
+*.orig
+
+# git shortlog -s -n
+#  	file for map author and committer names and email addresses
+#  	to canonical real names and email addresses
+/.mailmap
+
+##### IDE / Text editor
+
+# PhpStorm / IntelliJ
+.idea
+*.iml
+
+# Backup files
+*~
+