Update to jscep 2.0.1

 ° This fixes https://github.com/asyd/jscep-cli-jdk6/issues/9

Change-Id: I7c2c6f93c4c9581a53da543cbb5a220fb474f917
Update README

 * Add new usage information

 * Convert to .md (markdown) extension so that
   github will recognize it.

Change-Id: I9ee2df1c2c074f63fb8cb2be9c78f41703d8824c
Merge pull request #10 from pontillo/jscep2.0

Update to jscep 2.0.1