Build linux, darwin and windows binaries

Merge pull request remind101#12 from remind101/duration

Change default duration back to 1 hour

~/.aws/config is ini

Merge branch 'UseAWSSDK'

Merge pull request remind101#5 from remind101/clean

Clean AWS_ environment vars between evals.

Merge pull request remind101#3 from remind101/deal_with_dup_variables

Allow update of existing env vars

Merge pull request remind101#1 from remind101/security-token

Set AWS_SECURITY_TOKEN.

Update readme: console -> bash.