Update build and examples to use Amazon Redshift JDBC driver

[JoshRosen]

This commit updates the build and examples to use the Amazon Redshift JDBC Driver.

[JoshRosen]

AFAIK this use is compatible with the driver's license terms: https://s3.amazonaws.com/redshift-downloads/drivers/Amazon+Redshift+JDBC+Driver+License+Agreement.pdf

[JoshRosen]

Here, I chose to use the JDBC 4.0 driver instead of 4.1 in order to retain Java 6 support.

[codecov-io]

Current coverage is 85.90%

Merging #42 into master will increase coverage by +20.24% as of e5c9d48

@@            master    #42   diff @@
=====================================
  Files           10      9     -1
  Stmts          399    305    -94
  Branches        81     70    -11
  Methods          0      0       
=====================================
  Hit            262    262       
  Partial          0      0       
+ Missed         137     43    -94

Review entire Coverage Diff as of e5c9d48

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[JoshRosen]

This should now be ready for review + commit.

[JoshRosen]

This was LGTM'd offline, so I'm going to merge now and will rebase my other PR.