rebase

rebase

try to add specs for concat

try to add specs for concat

Update README.markdown

Update README.markdown

try to add specs for concat

try to add specs for concat

try to add specs for concat

try to add specs for concat

try to add specs for concat

try to add specs for concat

try to add specs for concat
remove concat param from defaults
first try
remove one unnecessary if
remove extra end
Merge pull request #63 from cristi1979/master

make spec for concat
Merge pull request #67 from emning/emptyparams

Skip keywords with empty string arguments