Release 0.15.1

Highlights:

• Several bug fixes
• Heron Python packaging
• Heron downloader
• Upgrade libevent, gflags, and glog to latest versions

Release Notes:

• Make metrics cache client in healthMgr fetch location from statemgr (#2232)
• Fix heronpy packaging (#2244)
• Remove unnecessary sub module BUILD files (#2240)
• Removing legacy kakfa connector (#2242)
• Convert kubernetes scheduler to use heron downloader. (#2223)
• Make bazel configure python3 friendly (#2228)
• Limit size of a single data tuple. (#2224)
• Fix yaml health manager config parsing error (#2226)
• 0.15.0 documentation release (#2221)
• Fix Join Bolt implementation (#2215)
• Ability to launch health manager on container-0 (#2203)
• Add a heron downloader to download and extract topology packages. (#2216)
• upgrade gflags and glog to newer versions (#2211)
• remove inputs from streamlet since the core streamlet class does not use it (#2214)
• Removed operation since it is unused (#2213)
• All of dsl methods need to output the same stream. This pr (#2212)
• Make the exception style compatible with both python2 and python3 (#2210)
• Fixed libtool install command in ubuntu 16.04 (#2208)
• Upgrade libevent to a more recent stable version (#2209)
• Replace all localhost by 127.0.0.1 (#2204)
• Documentation changes for 0.15.0 release (#2201)
• replace hard coded stmgr port in stmgr_unittest (#1852)
• Fix requests version, fix default env. (#2202)
• cleanup the dependencies for generating heron storm jar (#2191)
• Fix the stateful component overloaded functions in window bolt (#2199)
• Remove unused third party packages (#2198)
• Expose all API related classes in Python Packaging (#2197)
• Update cpplint to the latest release. Minor fixes in the code along the way (#2196)
• Add health manager operation mode (#2181)
• Fix log level and parameters (#2195)
• Fix python examples now that spouts have moved to connectors (#2193)
• Upgrade to gtest 1.8 (#2192)
• Follow pythonic idiom of _ instead of camelCase in DSL (#2190)
• Follow Python idiom of using _ instead of camelCase (#2189)
• HeronTupleSet needs src task id (#2187)
• Certain information should be printed only in debug mode (#2186)
• Fix import name in python examples (#2185)
• Create a connectors directory for spouts and bolts (sources/sinks) (#2176)
• Verify cluster name matches when submitting through apiserver. (#2184)
• Add topology resource unit tests. (#2179)
• Remove spi dependency from simulator since TopologyUtils moved from spi (#2182)