Add migrations directory and add current db schema as a first migration

Author: manuelwedler

.env.template

@@ -0,0 +1,7 @@
+##### DBMATE Configuration
+# Configure the database connection
+DATABASE_URL=postgres://username:password@127.0.0.1:5432/database_name?sslmode=disable
+
+# Required path configuration
+DBMATE_MIGRATIONS_DIR=./migrations
+DBMATE_SCHEMA_FILE=./database.sql