fix: use exact version 0.3.2 of grpc-inspect

[codesword]

grpc-inspect 0.3.3 can not process proto files with import. This in turn made it impossible to use mali with proto files that has import. This PR attempts to use grpc-inspect 0.3.2 which works well with proto import. The issue was raised here

[coveralls]

Coverage remained the same at 96.512% when pulling 9a7c1fb on andela:master into 20f0281 on malijs:master.

[bojand]

Hello, thanks for the PR. This should be addressed now with #17 and published as 0.4.1.