Update to import HTTP 0.7.0-0.7.99
Pull request #122. Upgrade to HTTP 0.7.0-0.7.99. This may solve some dependency issues.
Rerunning tests for dependencies is recommended.
Removes the need for capping the imported HTTP.jl version to 0.6.99.
Removes preliminary fixes with regards to incomplete transactions, which are now implemented in HTTP.jl.
Imports more functionality and types from HTTP.
Removes export of 'origin'.
Update to 'README' including some upgrade help.