Goa v3.0.3

The Goa community has contributed many fixes to Goa as adoption of v3 grows. This release builds on v3.0.1 and v3.0.2 and adds several more fixes. In particular:

• Nitin Mohan fixed a couple of issues with the generated OpenAPI specifications (#2141) (#2159).
• @ikawaha fixed a few issues with the generation of Go identifiers (#2144) (#2152) (#2172). @ikawaha also made it possible to use specific shas to point to Goa v3 in go.mod and made sure the code generation algorithms honored it (#2182).
• Ruggero added support for plain text to the default Goa encoder and decoder (#2165).
• Kaosisochukwu Uzokwe fixed a potential panic in the gRPC client method builder (#2186).
• Tim Adam moved the XRay test helpers into a separate package to avoid side effects when loading the testing package (#2190).
• Carl Quinn fixed an issue with the code generation of CLI arguments of type []byte (#2196).
• Raphael Simon fixed a couple of issues with the handling of array attributes in responses (#2200) (#2202).

v3.0.1 and v3.0.2 added a few other fixes. A notable addition contributed by @CuBiC in v3.0.1 is the ability to set scopes on basic auth and API key security schemes. The scopes can be defined in the design and are made available to the security enforcing functions at runtime (#2120).