Do not null lastWrite

May cause out of order writes

Allow amphp/file ^0.3

Fix explicit port in HTTP/2 Driver

Fixes #202.

v0.7.1

 - Fixed connection hangs if the process is forked while serving a request. See #182 and #192.

v0.7.0

 - Fixed incorrect log level warning.
 - Fixed issue with referenced IPC socket blocking server shutdown.
 - Added support for unix sockets.
 - Added support for wildcard server names such as `localhost:*`, `*:80` and `*:*`.
 - Fixed buggy HTTP/1 pipelining.
 - Handle promises returned from generators in the config file correctly.
 - Added `-u` / `--user` command line option.
 - Correctly decode URL parameters with `urldecode` instead of `rawurldecode`.
 - Fixed freeze of websocket reading with very low `maxFramesPerSecond` and `maxBytesPerMinute`.

v0.6.2

Retag of v0.6.0, as v0.6.1 has been tagged, but was supposed to be
v0.7.0.

Fix freeze of websocket reading with very low maxFramesPerSecond and …

…maxBytesPerMinute

Fix branch alias for dev-master

Merge pull request #145 from torinaki/add-worker-options

Add possibility to specify php options for workers

Fix for #134, prevent error on updates from already closed connections