Implement R/W Lock

Fix 479

Error stacktraces

Let's say we have following code:

```ruby
['T', 'A', 'I', 'P', 'E', 'I'].each(101) do |char|
...

Add float support to sleep()

Also improved the error handling, that would otherwise panic when not receiving the expected dat...

Add MatchData#to_h

Fix travis build running twice the test suite

This shows in travis that the `vm` test suite actually runs twice.

Add MatchData#to_h

Add tests for MatchData#to_h

[Experimental] Decimal class

Add checks the number of args in `require` and `require_relative`

- Implemented Float#to_df, but commented out

Add a test for Float#to_d

Change type reference i...

Add tests for Decimal#to_h and Decimal#to_hi

Update API doc for decimal.go

Add test for String#to_d

Add test for Decimal#to_a

Change Decimal#numerator and Decimal #denominator for returning decim...

Refactor int to Decimal and float to Decimal

Add tests for decimal.go

Add tests for decimal.go

Add internal DecimalValue() helper function
...

Remove trailing 0 from #to_s

Remove Decimal from Numeric

Update tests for decimal.go

Update t...

Add tests for decimal.go

Fix sample fractions

Remove duplicated '#fetch' from hash.go

Fix #508/update MatchData class

Improve error report

Implement Module(Class)#>

#509 Fix panic on `-e` option

Implement MatchData#length

Fix toplevel constant's bug: issue #491

Eliminate Go's standard regexp package from `String#fmt`

Make the snap classic (https://docs.snapcraft.io/reference/confinement)

Add a snapcraft.io build status badge

Add ConcurrentArray class