Rename "ConstructBuilder" to "FindRequestHandler"
as "ConstructBuilder" is a weak name that no longer accurately describes what this does
Also more detail in the error message
renamed "EndpointResolverTests.cs" to "RequestCoordinatorTests.cs"
as that is now the name of the class under test
Get access token from environment variables or app.config

This allows the 3 legged access token tests to be run from CI builds
Merge pull request #110 from AnthonySteele/rename_internal_method

Rename "ConstructBuilder" to "FindRequestHandler"
Merge pull request #111 from AnthonySteele/rename_rc_tests

renamed "EndpointResolverTests.cs" to "RequestCoordinatorTests.cs"
Merge pull request #112 from mattgray/crenna-oauth

Get access token from environment variables or app.config
Basic tests on get and post request handlers
Merge pull request #113 from AnthonySteele/request_handler_tests

Basic tests on get and post request handlers