Add #300 to changelog for 1.5
Add #300 to changelog for 1.5

remerge/sarama,pronix/sarama,Shopify/sarama,mailgun/sarama,yangfan876/sarama,scalingdata/sarama,cep21/sarama,kmiku7/sarama,jepst/sarama,raisemarketplace/sarama,Shopify/sarama,pronix/sarama,HelixEducation/sarama,vrischmann/sarama,Neuw84/sarama,VividCortex/sarama,vrischmann/sarama,jepst/sarama,jimmykuo/sarama,DataDog/sarama,crast/sarama,winlinvip/sarama,kmiku7/sarama,raisemarketplace/sarama,HelixEducation/sarama,Neuw84/sarama,mailgun/sarama,cep21/sarama,jimmykuo/sarama,DataDog/sarama,VividCortex/sarama,scalingdata/sarama,remerge/sarama,crast/sarama,winlinvip/sarama,yangfan876/sarama