Better error reporting and HTTP2 proxy fixes

This release contains an improvement to reporting an error status from gRPC stack by propagating it as part of the Status attached to the RequestException.

A breaking change to the config to require a scheme for a given base URI is introduced in order to fix certain situations where proxied request is sent to the service without a scheme causing request parsing failures.

0.5.6

This release contains:

• updated version of google/protobuf library
• minor bug fixes

Improves exception messages for connection failures

Merge pull request #26 from precariouspanther/connection-error-messages

Include connection error messages in exceptions

Remove default proxy configuration (off by default)

Removes the default value for proxy configuration as this option should be disabled by default.

Enable proxy support for H2 strategy

Adds support for explicit proxy configuration when using the H2 strategy.

0.5.2

Reduce dependency on php timer

0.5.2

Merge pull request #15 from precariouspanther/remove-phpunit-timer

Remove PHPUnit timer from grphp (causing package conflicts with PHPUnit)

0.5.1

• Suppress "expect: 100-continue" header on outbound cURL requests for the H2Proxy strategy

0.5.0

• Introduce new strategy patterns for communicating out to services, allowing either gRPC or H2Proxy for the client
• Adds H2Proxy strategy for utilizing nghttpx to proxy H1 requests into H2 gRPC requests without need of the PHP C
  extension
• Adds a new Error\Status class for representing gRPC error statuses
• Adds a new client request object for encapsulating contextual information about the outgoing request
• Adds new Header and HeaderCollection classes for representing HTTP headers both outbound and inbound

0.4.0

• Update to gRPC 1.9.x
• Get off BC gRPC fork now that root SSL memory leak issue is fixed (grpc/grpc#12706)