No such subcommand named "migratesql", corrected to "sqlmigrate"


Example:
Correct:
 "python manage.py sqlmigrate <app_name> <migration_no>"
incorrect:
 "python manage.py migratesql <app_name> <migration_no>"
Merge pull request #78 from plasx/patch-3

No such subcommand named "migratesql", corrected to "sqlmigrate"