Optional to for contract creating calls (#24)

* Use khex 1.0.0

* Use bouncycastle 1.66

* Use kotlin 1.3.72

* Allow 'to' to be null for contract creating calls

* Use gradle 6.6.1

* Use versions plugin 0.33.0

Author: ligi

build.gradle

@@ -1,7 +1,7 @@
 buildscript {
     ext {
         versions = [
-                kotlin                    : "1.3.61",
+                kotlin                    : "1.3.72",
                 moshi                     : '1.8.0',
                 okhttp                    : '3.11.0',
                 jupiter                   : '5.6.0',
@@ -36,7 +36,7 @@ buildscript {
 
     dependencies {
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$versions.kotlin"
-        classpath 'com.github.ben-manes:gradle-versions-plugin:0.27.0'
+        classpath 'com.github.ben-manes:gradle-versions-plugin:0.33.0'
         // How can we move this to the sample folder
         //classpath deps.android.gradlePlugin
     }

gradle/wrapper/gradle-wrapper.jar

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.1.1-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.6.1-all.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

gradle/wrapper/gradle-wrapper.properties

@@ -82,6 +82,7 @@ esac
 
 CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
 
+
 # Determine the Java command to use to start the JVM.
 if [ -n "$JAVA_HOME" ] ; then
     if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
@@ -129,6 +130,7 @@ fi
 if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
     APP_HOME=`cygpath --path --mixed "$APP_HOME"`
     CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+
     JAVACMD=`cygpath --unix "$JAVACMD"`
 
     # We build the pattern for arguments to be converted via cygpath

gradlew

@@ -29,6 +29,9 @@ if "%DIRNAME%" == "" set DIRNAME=.
 set APP_BASE_NAME=%~n0
 set APP_HOME=%DIRNAME%
 
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
 @rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
 set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
 
@@ -37,7 +40,7 @@ if defined JAVA_HOME goto findJavaFromJavaHome
 
 set JAVA_EXE=java.exe
 %JAVA_EXE% -version >NUL 2>&1
-if "%ERRORLEVEL%" == "0" goto init
+if "%ERRORLEVEL%" == "0" goto execute
 
 echo.
 echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
@@ -51,7 +54,7 @@ goto fail
 set JAVA_HOME=%JAVA_HOME:"=%
 set JAVA_EXE=%JAVA_HOME%/bin/java.exe
 
-if exist "%JAVA_EXE%" goto init
+if exist "%JAVA_EXE%" goto execute
 
 echo.
 echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
@@ -61,28 +64,14 @@ echo location of your Java installation.
 
 goto fail
 
-:init
-@rem Get command-line arguments, handling Windows variants
-
-if not "%OS%" == "Windows_NT" goto win9xME_args
-
-:win9xME_args
-@rem Slurp the command line arguments.
-set CMD_LINE_ARGS=
-set _SKIP=2
-
-:win9xME_args_slurp
-if "x%~1" == "x" goto execute
-
-set CMD_LINE_ARGS=%*
-
 :execute
 @rem Setup the command line
 
 set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
 
+
 @rem Execute Gradle
-"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
 
 :end
 @rem End local scope for the variables with windows NT shell

gradlew.bat

@@ -9,9 +9,9 @@ repositories {
 dependencies {
     implementation "org.jetbrains.kotlin:kotlin-stdlib:$versions.kotlin"
 
-    implementation "com.github.komputing:khex:1.0.0-RC6"
+    implementation "com.github.komputing:khex:1.0.0"
 
-    implementation 'org.bouncycastle:bcprov-jdk15on:1.64'
+    implementation 'org.bouncycastle:bcprov-jdk15on:1.66'
 
     implementation 'com.squareup.moshi:moshi:1.8.0'
     // TODO: it would be better to use the generated adapter by moshi

lib/build.gradle

@@ -121,7 +121,7 @@ interface Session {
         data class SendTransaction(
             val id: Long,
             val from: String,
-            val to: String,
+            val to: String?,
             val nonce: String?,
             val gasPrice: String?,
             val gasLimit: String?,