Any person or persons, jointly or severally, aggrieved by any decision of the board of adjustment, or any taxpayer, or any officer, department, board, or bureau of the municipality, may present to the district court a petition duly verified, setting forth that such decision is illegal, in whole or in part, and specifying the grounds of such illegality. Such petition must be presented to the court within fifteen days after the filing of the decision in the office of the board. Upon the filing of such petition a summons shall be issued and be served upon the board of adjustment, together with a copy of the petition. Return of service shall be made within four days after the issuance of the summons. Within ten days after the return day of such summons, the board of adjustment shall file an answer to said petition which shall admit or deny the substantial averments of the petition, and shall state the contentions of the board with reference to the matters in dispute as disclosed by the petition. The answer shall be verified in like manner as required for the petition. At the expiration of the time for filing answer, the court shall proceed to hear and determine the cause without delay and shall render judgment thereon according to the forms of law. If, upon the hearing, it shall appear to the court that testimony is necessary for the proper disposition of the matter, it may take evidence or appoint a referee to take such evidence as it may direct and report the same to the court with his findings of fact and conclusions of law, which shall constitute a part of the proceedings upon which the determination of the court shall be made. The court may reverse or affirm, wholly or partly, or may modify the decision brought up for review. Said appeal to the district court shall not stay proceedings upon the decision appealed from, but the court may, on application, on notice to the board and on due cause shown, grant a restraining order. Any appeal from such judgment of the district court shall be prosecuted in accordance with the general laws of the state regulating appeals in actions at law.