Change readers #each implementations to allow creation of iterators
by calling Enumerable methods (#each, #each_with_index, etc.)
without a block.
Added travis badge
Merge branch 'master' into ci-enumerators

Pulling in travis stuff
Merge branch 'master' into ci-enumerators
Merge branch 'master' into ci-enumerators
Merge branch 'master' into ci-enumerators
Merge branch 'master' into ci-enumerators
Merge branch 'master' into ci-enumerators
Merge branch 'master' into ci-enumerators
Merge branch 'master' into ci-enumerators
Merge pull request #16 from ruby-marc/ci-enumerators

Ci enumerators
rewrite ControlField.control_tag? to just test strings, not fail on data tag strings that #to_i to numbers
bump version to 0.6.0
noticed a small typo
test file should require stringio if it uses it
for too-long records, MARC::Writer still writes records ForgivingReader can read now
MARC::Writer, optional allow_oversized=false to raise on oversized writing
tests, don't try to do encoding related tests unless we're in 1.9.3
Writer, change default allow_oversized==false
Add a rubygem release badge to README