0.2.0rc1

Jumping to 0.2 for this big update #1117. 0.1.* will continue to receive bug-fixes

• timezone cache performance massively improved. Thanks @fredrik-corneliusson #1113 #1112 #1109 #1105 #1099
• price repair feature #1110
• fix merging of dividends/splits with prices #1069 #1086 #1102
• fix Yahoo returning latest price interval across 2 rows #1070
• optional: raise price errors as exceptions: download(..., raise_errors=True) #1104
• add proper unit tests #1069