Issue 196: Bump bk version to 4.6.0-SNAPSHOT

[sijie]

Descriptions of the changes in this PR:

• Update the bk version to 4.6.0-SNAPSHOT to align the development of 0.6.0
• in bk 4.6.0, ZkVersion is generalized as LongVersion. Change the usage to LongVersion.

[jiazhai]

There seems be a CI test case error:

Tests run: 6, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 10.645 sec - in org.apache.distributedlog.TestBKSyncLogReader
Running org.apache.distributedlog.TestDistributedLogConfiguration
Tests run: 5, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 0.327 sec <<< FAILURE! - in org.apache.distributedlog.TestDistributedLogConfiguration
loadStreamConfNullOverrides(org.apache.distributedlog.TestDistributedLogConfiguration)  Time elapsed: 0.01 sec  <<< ERROR!
org.apache.commons.configuration.ConfigurationRuntimeException: java.lang.reflect.InvocationTargetException
    at org.apache.distributedlog.TestDistributedLogConfiguration.loadStreamConfNullOverrides(TestDistributedLogConfiguration.java:87)
Caused by: java.lang.reflect.InvocationTargetException
    at org.apache.distributedlog.TestDistributedLogConfiguration.loadStreamConfNullOverrides(TestDistributedLogConfiguration.java:87)
Caused by: org.apache.commons.configuration.ConfigurationRuntimeException: java.lang.CloneNotSupportedException: org.apache.commons.configuration.MapConfiguration$1 does not implement Cloneable
    at org.apache.distributedlog.TestDistributedLogConfiguration.loadStreamConfNullOverrides(TestDistributedLogConfiguration.java:87)
Caused by: java.lang.CloneNotSupportedException: org.apache.commons.configuration.MapConfiguration$1 does not implement Cloneable
    at org.apache.distributedlog.TestDistributedLogConfiguration.loadStreamConfNullOverrides(TestDistributedLogConfiguration.java:87)

[sijie]

@jiazhai I see. I think the bk configuration was changed in 4.6.0. so I need to fix this as well

nice catch.

[jiazhai]

Close this, since this change is contained in PR #198 .