Fix create_continuous_query method for Ruby 1.9 compatibility

[sebcoetzee]

@dmke please look at this, this is causing an error when requiring the gem.

/Users/sebastiancoetzee/.rvm/gems/ruby-1.9.3-p545@insight-app/gems/activesupport-3.2.22.2/lib/active_support/dependencies.rb:251:in `require': /Users/sebastiancoetzee/.rvm/gems/ruby-1.9.3-p545@insight-app/gems/influxdb-0.3.3/lib/influxdb/query/continuous_query.rb:13: syntax error, unexpected tLABEL (SyntaxError)
...atabase, query, resample_every: nil, resample_for: nil)
...                               ^
/Users/sebastiancoetzee/.rvm/gems/ruby-1.9.3-p545@insight-app/gems/influxdb-0.3.3/lib/influxdb/query/continuous_query.rb:13: Can't assign to nil
...se, query, resample_every: nil, resample_for: nil)
...                               ^
/Users/sebastiancoetzee/.rvm/gems/ruby-1.9.3-p545@insight-app/gems/influxdb-0.3.3/lib/influxdb/query/continuous_query.rb:31: syntax error, unexpected keyword_end, expecting $end

[sebcoetzee]

@dmke Pardon, I see now that this is a Ruby < 2 issue with keyword arguments.

[dmke]

Indeed, support for Ruby < 2.0 was dropped with v0.2.0.

[dmke]

Would you mind amend your PR to use an options={} argument, so that the tests continue to work?

Since there are now a few 1.9 requests within a few days, I'm reconsidering 1.9 support.

[sebcoetzee]

Thanks for the quick response @dmke