Creates new AWS Ruby SDK api commands and tests

[ebozduman]

Since Minio Ruby SDK for Amazon S3 is not available yet, I wrote the basic functionality as part of the Mint testing effort. Then created test cases which basically call these commands and check if the expected values are returned. I took Minio Java SDK for Amazon S3 list of command as a base, and created Ruby SDK commands using the same names. Here is the list of commands, for which tests created, in this pull request. Bucket Operations:

• makeBucket
• listBuckets
• bucketExists?
• removeBucket
• listObjects

Object Operations:

• getObject
• putObject
• copyObject
• statObject
• removeObjects
• removeObject

[nitisht]

Tabbing looks off @ebozduman . Need to probably run the lint tool

[nitisht]

any reviews here @harshavardhana