Removed aws-sdk from package.json to fix error #1241 + minor README fix

[itsdrew]

Issue #, if available: #1241 Description of changes:

Removed aws-sdk dependency from package.json to fix 'Storage, missing credentials in config' error when uploading to s3.

Changed 'cd aws-amplify-vue-sample' to the correct path after cloning the repo: 'cd was-amplify-vue' in README.md.

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