S3 2.0 - Round 2

Enhancements:
1) New Task: amazon-s3-copyFile that will allow you to copy a file between buckets within S3
2) Incorporated a string (bucketName) requirement to method BucketExists to allow for validating the existence of more than one bucket.
3) Incorporated a string (fileKey) requirement to method FileExists to allow for validating the existence of multiple filenames.
4) Formatting changes on output statements

Bug Fixes:
1) Added a test to make sure a bucket exists before attempting to delete it
2) Corrected an issue where you were unable to delete files if they were inside a sub directory of the bucket
3) Added back in the CreateBucket method to the deprecated 'amazon-s3' Task to more closely mimic the original behavior of this Task