HTTP header behaviour in test cases differs from that in spec about pact-specification

[uglyog]

@bethesque @mefellows we need to update the spec here, and make it consistent. I've looked at the JVM header matching code, and I don't think it is correct:

1. Compare header keys case insensitive
2. Compare header contents base on:
   2.1 For cookie, split the value by semi-colon into a whitespace trimmed list, and the header matches if all the actual values contain the expected value at the same position
   2.2 For content-type, split the value by semi-colon and trim white-space, then compare the first value:
   * if the first values differ, it is a mismatch
   * if the first values are the equal, and the tails are both empty, it is a match
   * otherwise, split the tails by = (stripping white-space) into a key-value map and compare case sensitive
   2.3 otherwise strip any white-space after the commas in the values and compare case sensitive.

This looks wrong, but it has worked to date because 99% of header values don't have multiple values and don't use parameters.

[uglyog]

In general, we should refer to the HTTP spec to define the rules. The pact spec is clearly wrong.

[bethesque]

No worries, what should we change it to?