PARQUET-57 - Update dev README to clarify two points

Author: Brock Noland <brock@apache.org>

Closes #26 from brockn/PARQUET-57 and squashes the following commits:

ffb2a9a [Brock Noland] Prompt for jira user/pass if not set
0135cdd [Brock Noland] Fix spelling
171d714 [Brock Noland] PARQUET-57 - Update dev README to clarify two points
PARQUET-13: The `-d` option for `parquet-schema` shouldn't have optional argument

Author: Cheng Lian <lian.cs.zju@gmail.com>

Closes #11 from liancheng/fix-cli-arg and squashes the following commits:

85a5453 [Cheng Lian] Reverted the dummy change
47ce817 [Cheng Lian] Dummy change to trigger Travis
1c0a244 [Cheng Lian] The `-d` option for `parquet-schema` shouldn't have optional argument
PARQUET-59: Fix parquet-scrooge test on hadoop-2.

Author: Ryan Blue <rblue@cloudera.com>

Closes #27 from rdblue/PARQUET-59-fix-scrooge-test-on-hadoop-2 and squashes the following commits:

ac34369 [Ryan Blue] PARQUET-59: Fix parquet-scrooge test on hadoop-2.