Travis cleanup (#326)

* bumping SBT version for ide; fixing some warnings per https://www.scala-sbt.org/1.x/docs/Migrating-from-sbt-013x.html#slash

* fixing a bug in if-then-else

build.sbt

@@ -19,10 +19,10 @@ scalacOptions := Seq("-unchecked", "-deprecation")
 
 libraryDependencies += "org.scala-lang.modules" %% "scala-parser-combinators" % "1.1.2"
 
-assemblyJarName in assembly := "obsidianc.jar"
+assembly / assemblyJarName := "obsidianc.jar"
 
-unmanagedResourceDirectories in Compile += baseDirectory.value / "Obsidian_Runtime/src/main/java/Runtime/edu/cmu/cs/obsidian"
-includeFilter in (Compile, unmanagedResources) := "*.obs"
+Compile / unmanagedResourceDirectories += baseDirectory.value / "Obsidian_Runtime/src/main/java/Runtime/edu/cmu/cs/obsidian"
+Compile /  unmanagedResources / includeFilter := "*.obs"
 
 /* Don't throw TrapExitSecurityException.
  * Also, allow passing return code through SBT without
@@ -44,12 +44,12 @@ libraryDependencies += "org.apache.commons" % "commons-io" % "1.3.2"
 /* settings for assembly */
 
 // don't get confused about multiple META-INF/MANIFEST.MF
-assemblyMergeStrategy in assembly := {
+assembly / assemblyMergeStrategy := {
     case PathList("META-INF", "MANIFEST.MF") => MergeStrategy.discard
     case x if x.contains("module-info.class") => MergeStrategy.discard // https://stackoverflow.com/questions/54834125/sbt-assembly-deduplicate-module-info-class
     case x if x.contains("io.netty.versions.properties") => MergeStrategy.discard
     case x =>
-        val oldStrategy = (assemblyMergeStrategy in assembly).value
+        val oldStrategy = ( assembly / assemblyMergeStrategy).value
     	oldStrategy(x)
 }
 

src/main/scala/edu/cmu/cs/obsidian/codegen/Util.scala

@@ -13,7 +13,7 @@ object Util {
   def callvaluecheck: YulStatement = codegen.If(FunctionCall(Identifier("callvalue"), Seq()), Block(Seq(ExpressionStatement(FunctionCall(Identifier("revert"), Seq(ilit(0), ilit(0)))))))
   def unary(n: String, e: Expression): Expression = FunctionCall(Identifier(n),Seq(e))
   def binary(n : String, e1: Expression, e2: Expression): Expression = FunctionCall(Identifier(n), Seq(e1, e2))
-  def store_then_ret(retvar:Identifier, e:Expression) = Seq(edu.cmu.cs.obsidian.codegen.Assignment(Seq(retvar),e), ExpressionStatement(e))
+  def store_then_ret(retvar:Identifier, e:Expression) = Seq(edu.cmu.cs.obsidian.codegen.Assignment(Seq(retvar),e)) //todo this may not be needed once i work out more cases
 
   val true_lit: Literal = blit(true)
   val false_lit: Literal = blit(false)