Add clear result class

[davidrpugh]

@bherd-rb Based on your work on the Java side, this PR adds a ClearResult class which replaces the Tuple2 return type previously used for the clear method.

[davidrpugh]

@bherd-rb I am stuck trying to fix a compile error in the Java code. Specifically in src/functional/java/org/economicsl/auctions/Sandbox.java I am trying to print out the resulting fills...

// after inserting orders, now we can define the pricing rule...
DoubleAuction<GoogleStock> auction = withOrderBook5.withUniformPricing(midPointPricing);
ClearResult<GoogleStock, DoubleAuction<GoogleStock>> result = auction.clear();
result.fills().map(fills -> fills.foreach(fill -> System.out.println(fill)));

...and am getting a compile error...

[info] Compiling 11 Scala sources and 3 Java sources to C:\Users\pughdr\Research\scalabm\auctions\target\scala-2.12\functional-classes...
[error] C:\Users\pughdr\Research\scalabm\auctions\src\functional\java\org\economicsl\auctions\Sandbox.java:108:  error: incompatible types: inferred type does not conform to upper bound(s)
[error]         result.fills().map(fills -> fills.foreach(fill -> System.out.println(fill)));
[error]                           ^
[error] (functional:compileIncremental) javac returned nonzero exit code
[error] Total time: 15 s, completed Apr 26, 2017 1:43:08 PM

thoughts?

[bherd-rb]

@davidrpugh It works well in my case. Are you compiling with Maven or sbt?

[davidrpugh]

@bherd-rb I am using SBT to compile. I am getting the same error as Travis.

[davidrpugh]

@bherd-rb I think this is now ready for merge. I made some cosmetic changes to Sandbox.java in order to get everything to compile. Still not certain why is worked for you (compiling with Maven) but not for me (compiling with SBT)...this is a bit worrying!

[bherd-rb]

@davidrpugh It is a bit worrying, yes. I'll take a look at the issue when I'm back from the US.